The 1839 Treaty of London was the document cited by Britain when they presented Germany with an ultimatum not to invade Belgium on August 3, 1914. I have found several websites which quote the relevant portions of the treaty, but I could not find a website that had the treaty in its entirety. The following was taken from a 1915 book entitled England's Guarantee to Belgium and Luxemburg, with the Full Text of the Treaties. Publishing a facsimile of the treaty held in the British National Archives is not helpful since it is in French.

The first part of the treaty which starts with "Treaty between Great Britain. . ." contains three articles that list out all the signatures, dates, and states that the articles of the treaty are "placed under the guarantee of their said Majesties." These majesties are the kings and queens of Great Britain, Austria, France, Prussia, and Russia.

The second part of the treaty starts with "Annex to the Treaty of London. . ." and contains 24 articles that define the boundaries for the state of Belgium along with shipping rights, duties, debts, and other details for the new country. Article VII of the Annex to the Treaty says, "Belgium, within the limits specified in Articles I, II, and IV, shall form an independent and perpetually neutral State. It shall be bound to observe such neutrality towards all other States."

A similar treaty was signed the same day between the guaranteeing powers and the Netherlands. The following is the Treaty of London involving Belgium and its Annex in their entirety.

Treaty between Great Britain, Austria, France, Prussia, and Russia, on the one part, and Belgium, on the other.

Signed at London, April 19, 1839.

In the Name of the Most Holy and Indivisible Trinity.

Her Majesty the Queen of the United Kingdom of Great Britain and Ireland, His Majesty the Emperor of Austria, King of Hungary and Bohemia, His Majesty the King of the French, His Majesty the King of Prussia, and His Majesty the Emperor of all the Russias, taking into consideration, as well as His Majesty the King of the Belgians, their Treaty concluded at London on the 15th of November, 1831, as well as the Treaties signed this day between their Majesties the Queen of the United Kingdom of Great Britain and Ireland, the Emperor of Austria, King of Hungary and Bohemia, the King of the French, the King of Prussia, and the Emperor of all the Russias, on the one part, and His Majesty the King of the Netherlands, Grand Duke of Luxembourg, on the other part, and between His Majesty the King of the Belgians and His said Majesty the King of the Netherlands, Grand Duke of Luxembourg, their said Majesties have named as their Plenipotentiaries, that is to say :

[Here follow the names.]

Article I.

Her Majesty the Queen of the United Kingdom of Great Britain and Ireland, His Majesty the Emperor of Austria, King of Hungary and Bohemia, His Majesty the King of the French, His Majesty the King of Prussia, and His Majesty the Emperor of all the Russias, declare, that the Articles hereunto annexed, and forming the tenour of the Treaty concluded this day between His Majesty the King of the Belgians and His Majesty the King of the Netherlands, Grand Duke of Luxembourg, are considered as having the same force and validity as if they were textually inserted in the present Act, and that they are thus placed under the guarantee of their said Majesties.

Article II.

The Treaty of the 15th of November, 1831, between their Majesties the Queen of the United Kingdom of Great Britain and Ireland, the Emperor of Austria, King of Hungary and Bohemia, the King of the French, the King of Prussia, and the Emperor of all the Russias, and His Majesty the King of the Belgians, is declared not to be obligatory upon the High Contracting Parties.

Article III.

The present Treaty shall be ratified, and the ratifications shall be exchanged at London at the expiration of six weeks, or sooner if possible. This exchange shall take place at the same time as that of the ratifications of the Treaty between Belgium and Holland. In witness whereof, the respective Plenipotentiaries have signed the present Treaty, and have affixed thereto the seal of their Arms.

Done at London, the nineteenth day of April, in the year of our Lord one thousand eight hundred and thirty-nine.

(L.S.) Palmerston. (L.S.) Senfft. (L.S.) H. Sebastiani. (L.S.) Bulow. (L.S.) Pozzo di Borgo. (L.S.) Sylvan van de Weyer.

Annex to the Treaty of London signed at London, on the 19th April 1839, between Great Britain, Austria, France, Prussia, and Russia, on the one part, and the Netherlands, on the other part.

Article I.

The Belgian territory shall be composed of the provinces of

South Brabant; Liege; Namur; Hainault; West Flanders; Antwerp; and Limbourg;

such as they formed part of the United Kingdom of the Netherlands constituted in 1815, with the exception of those districts of the province of Limbourg which are designated in Article IV.

The Belgian territory shall, moreover, comprise that part of the Grand Duchy of Luxembourg which is specified in Article II.

Article II.

In the Grand Duchy of Luxembourg, the limits of the Belgian territory shall be such as will be hereinafter described, viz.

Commencing from the frontier of France between Rodange, which shall remain to the Grand Duchy of Luxembourg, and Athus, which shall belong to Belgium, there shall be drawn, according to the annexed map, a line which, leaving to Belgium the road from Arlon to Longwy, the town of Arlon with its district, and the road from Arlon to Bastogne, shall pass between Messancy, which shall be on the Belgian territory, and Clemancy, which shall remain to the Grand Duchy of Luxembourg, terminating at Steinfort, which place shall also remain to the Grand Duchy. From Steinfort this line shall be continued in the direction of Eischen, Hecbus, Guirsch, Ober-Pallen, Grende, Nothomb, Parette, and Perle, as far as Martelange; Hecbus, Guirsch, Grende, Nothomb, and Parette, being to belong to Belgium, and Eischen, Ober-Pallen, Perle, and Martelange, to the Grand Duchy. From Martelange the said line shall follow the course of the Sure, the water way (thalweg) of which river shall serve as the limit between the two States, as far as opposite to Tintange, from whence it shall be continued, as directly as possible, towards the present frontier of the Arrondissement of Diekirch, and shall pass between Surret, Harlange, and Tarchamps, which places shall be left to the Grand Duchy of Luxembourg, and Honville, Livarchamps, and Loutremange, which places shall form part of the Belgian territory. Then having, in the vicinity of Doncols and Soulez, which shall remain to the Grand Duchy, reached the present boundary of the Arrondissement of Diekirch, the line in question shall follow the said boundary to the frontier of the Prussian territory. All the territories, towns, fortresses, and places situated to the west of this line, shall belong to Belgium; and all the territories, towns, fortresses, and places situated to the east of the said line, shall continue to belong to the Grand Duchy of Luxembourg.

It is understood, that in making out this line, and in conforming as closely as possible to the description of it given above, as well as to the delineation of it on the map, which, for the sake of greater clearness, is annexed to the present Article, the Commissioners of demarcation, mentioned in Article V, shall pay due attention to the localities, as well as to the mutual necessity for accommodation which may result therefrom.

Article III.

In return for the cessions made in the preceding Article, there shall be assigned to His Majesty the King of the Netherlands, Grand Duke of Luxembourg, a territorial indemnity in the province of Limbourg.

Article IV.

In execution of that part of Article I which relates to the province of Limbourg, and in consequence of the cessions which His Majesty the King of the Netherlands, Grand Duke of Luxembourg, makes in Article II, His said Majesty shall possess, either to be held by him in his character of Grand Duke of Luxembourg, or for the purpose of being united to Holland, those territories, the limits of which are hereinafter described.

On the right bank of the Meuse; to the old Dutch enclaves upon the said bank in the province of Limbourg, shall be united those districts of the said province upon the same bank, which did not belong to the States General in 1790; in such wise that the whole of that part of the present province of Limbourg, situated upon the right bank of the Meuse, and comprised between that river on the west, the frontier of the Prussian territory on the east, the present frontier of the province of Liege on the south, and Dutch Guelderland on the north, shall henceforth belong to His Majesty the King of the Netherlands, either to be held by him in his character of Grand Duke of Luxembourg, or in order to be united to Holland. On the left bank of the Meuse; commencing from the southernmost point of the Dutch province of North Brabant, there shall be drawn, according to the annexed map, a line which shall terminate on the Meuse above Wessem, between that place and Stevenswaardt, at the point where the frontiers of the present Arrondissements of Ruremonde and Maestricht meet on the left bank of the Meuse; in such manner that Bergerot, Stamproy, Neer-Itteren, Ittervoordt, and Thorn, with their districts, as well as all the other places situated to the north of this line, shall form part of the Dutch territory.

The old Dutch enclaves in the province of Limbourg, upon the left bank of the Meuse, shall belong to Belgium, with the exception of the town of Maestricht, which, together with a radius of territory, extending twelve hundred toises from the outer glacis of the fortress, on the said bank of this river, shall continue to be possessed in full sovereignty and property by His Majesty the King of the Netherlands.

Article V.

His Majesty the King of the Netherlands, Grand Duke of Luxembourg, shall come to an agreement with the Germanic Confederation, and with the Agnates of the House of Nassau, as to the application of the stipulations contained in Articles III and IV, as well as upon all the arrangements which the said Articles may render necessary, either with the abovementioned Agnates of the House of Nassau, or with the Germanic Confederation.

Article VI.

In consideration of the territorial arrangements above stated, each of the two parties renounces reciprocally, and for ever, all pretension to the territories, towns, fortresses, and places situated within the limits of the possessions of the other party, such as those limits are described in Articles I, II, and IV.

The said limits shall be marked out in conformity with those Articles by Belgian and Dutch Commissioners of demarcation, who shall meet as soon as possible in the town of Maestricht.

Article VII.

Belgium, within the limits specified in Articles I, II, and IV, shall form an independent and perpetually neutral State. It shall be bound to observe such neutrality towards all other States.

Article VIII.

The drainage of the waters of the two Flanders shall be regulated between Holland and Belgium, according to the stipulations on this subject contained in Article VI of the definitive Treaty concluded between His Majesty the Emperor of Germany and the States General, on the 8th of November 1785; and in conformity with the said Article, Commissioners, to be named on either side, shall make arrangements for the application of the provisions contained in it.

Article IX.

§ 1. The provisions of Articles CVIII to CXVII inclusive of the General Act of the Congress of Vienna, relative to the free navigation of navigable rivers, shall be applied to those navigable rivers which separate the Belgian and the Dutch territories, or which traverse them both.

§ 2. So far as regards specially the navigation of the Scheldt, and of its mouths, it is agreed, that the pilotage and the buoying of its channel, as well as the conservation of the channels of the Scheldt below Antwerp, shall be subject to a joint superintendence; and that this joint superintendence shall be exercised by Commissioners to be appointed for this purpose by the two parties. Moderate pilotage dues shall be fixed by mutual agreement, and those dues shall be the same for the vessels of all nations.

In the meantime, and until these dues shall be fixed, no higher pilotage dues shall be levied than those which have been established by the tariff of 1829, for the mouths of the Meuse from the high sea to Helvoet, and from Helvoet to Rotterdam, in proportion to the distances. It shall be at the choice of every vessel proceeding from the high sea to Belgium, or from Belgium to the high sea, to take what pilot she pleases; and upon the same principle, it shall be free for the two countries to establish along the whole course of the Scheldt, and at its mouth, such pilotage establishments as shall be deemed necessary for furnishing pilots. Everything relating to these establishments shall be determined by the regulation to be concluded in conformity with § 6 hereinafter following. These establishments shall be placed under the joint superintendence mentioned in the beginning of the present paragraph. The two Governments engage to preserve the navigable channels of the Scheldt, and of its mouths, and to place and maintain therein the necessary beacons and buoys, each for its own part of the river.

§ 3. There shall be levied by the Government of the Netherlands, upon the navigation of the Scheldt and of its mouths, a single duty of florins 1.50 per ton; that is to say, florins 1.12 on vessels which, coming from the high sea, shall ascend the Western Scheldt in order to proceed to Belgium by the Scheldt, or by the Canal of Terneuze; and of florins 0.38 per ton on vessels which, coming from Belgium by the Scheldt or by the Canal of Terneuze, shall descend the Western Scheldt in order to proceed to the high sea. And in order that the said vessels may not be subject to any visit, nor to any delay or hindrance whatever within the Dutch waters, either in ascending the Scheldt from the high sea, or in descending the Scheldt in order to reach the high sea, it is agreed that the collection of the duty abovementioned shall take place by Dutch agents at Antwerp and at Terneuze. In the same manner, vessels arriving from the high sea in order to proceed to Antwerp by the Western Scheldt, and coming from places suspected in regard to health, shall be at liberty to continue their course without hindrance or delay, accompanied by one health guard, and thus to proceed to the place of their destination. Vessels proceeding from Antwerp to Terneuze, and vice versa, or carrying on in the river itself coasting trade or fishery (in such manner as the exercise of the latter shall be regulated in pursuance of § 6 hereinafter) shall not be subjected to any duty.

§ 4. The branch of the Scheldt called the Eastern Scheldt not being in its present state available for the navigation from the high sea to Antwerp and Terneuze, and vice versa, but being used for the navigation between Antwerp and the Rhine, this eastern branch shall not be burthened, in any part of its course, with higher duties or tolls than those which are levied, according to the tariffs of Mayence of the 31st of March, 1831, upon the navigation from Gorcum to the high sea, in proportion to the distances.

§ 5. It is also agreed that the navigation of the intermediate channels between the Scheldt and the Rhine, in order to proceed from Antwerp to the Rhine, and vice versa, shall continue reciprocally free, and that it shall be subject only to moderate tolls, which shall be the same for the commerce of the two countries.

§ 6. Commissioners on both sides shall meet at Antwerp in the space of one month, as well to determine the definitive and permanent amount of these tolls, as to agree upon a general regulation for the execution of the provisions of the present Article, and to include therein a provision for the exercise of the right of fishing and of trading in fish, throughout the whole extent of the Scheldt, on a footing of perfect reciprocity and equality in favour of the subjects of the two countries.

§ 7. In the meantime, and until the said regulations shall be prepared, the navigation of the Meuse and of its branches shall remain free to the commerce of the two countries, which shall adopt provisionally, in this respect, the tariffs of the Convention signed at Mayence on the 31st of March, 1831, for the free navigation of the Rhine, as well as the other provisions of that Convention, so far as they may be applicable to the said river.

§ 8. If natural events or works of art should hereafter render impracticable the lines of navigation mentioned in the present Article, the Government of the Netherlands shall assign to Belgian navigation other lines equally safe, and equally good and commodious, instead of the said lines of navigation become impracticable.

Article X.

The use of the canals which traverse both countries shall continue to be free and common to the inhabitants of both. It is understood that they shall enjoy the use of the same reciprocally, and on equal conditions; and that on either side moderate duties only shall be levied upon the navigation of the said canals.

Article XI.

The commercial communications through the town of Maestricht, and through Sittardt, shall remain entirely free, and shall not be impeded under any pretext whatsoever.

The use of the roads which, passing through these towns lead to the frontiers of Germany, shall be subject only to the payment of moderate turnpike tolls, for the repair of the said roads, so that the transit commerce may not experience any obstacle thereby, and that by means of the tolls abovementioned these roads may be kept in good repair, and fit to afford facilities to that commerce.

Article XII.

In the event of a new road having been constructed, or a new canal cut, in Belgium, terminating at the Meuse, opposite the Dutch canton of Sittardt, in that case Belgium shall be entitled to demand of Holland, who, on the other hand, shall not in such case refuse her consent, that the said road, or the said canal, shall be continued, according to the same plan, and entirely at the cost and charge of Belgium, through the canton of Sittardt, to the frontiers of Germany. This road or canal, which shall be used only as a commercial communication, shall be constructed, at the option of Holland, either by engineers and workmen whom Belgium shall obtain permission to employ for that purpose in the canton of Sittardt, or by engineers and workmen to be furnished by Holland, and who shall execute the works agreed upon at the expense of Belgium; the whole without any charge whatsoever to Holland, and without prejudice to her exclusive rights of sovereignty over the territory which may be traversed by the road or canal in question.

The two parties shall fix, by mutual agreement, the amount and the mode of collection of the duties and tolls which should be levied upon the said road or canal.

Article XII.

§ 1. From and after the 1st of January, 1839, Belgium, with reference to the division of the public debt of the Kingdom of the Netherlands, shall remain charged with the sum of 5,000,000 of Netherland florins of annual interest, the capital of which shall be transferred from the debit of the Great Book of Amsterdam, or from the debit of the General Treasury of the Kingdom of the Netherlands, to the debit of the Great Book of Belgium.

§ 2. The capitals transferred, and the annuities inscribed upon the debit of the Great Book of Belgium, in consequence of the preceding paragraph, to the amount of the total sum of 5,000,000 Netherland florins of annual interest, shall be considered as forming part of the Belgian National Debt; and Belgium engages not to admit, either at present or in future, any distinction between this portion of her public debt arising from her union with Holland, and any other Belgian national debt already created, or which may be created hereafter.

§ 3. The payment of the abovementioned sum of 5,000,000 Netherland florins of annual interest, shall take place regularly every six months, either at Brussels or at Antwerp, in ready money, without deduction of any kind whatsoever, either at present or in future.

§ 4. In consideration of the creation of the said sum of 5,000,000 florins of annual interest, Belgium shall be released from all obligation towards Holland, on account of the division of the public debt of the Kingdom of the Netherlands.

§ 5. Commissioners to be named on both sides, shall meet within the space of fifteen days in the town of Utrecht, in order to proceed to the transfer of the capitals and annual interest, which upon the division of the public debt of the Kingdom of the Netherlands, are to pass to the charge of Belgium, up to the amount of 5,000,000 florins of annual interest.

They shall also proceed to deliver up the archives, maps, plans, and other documents whatsoever which belong to Belgium, or which relate to her administration.

Article XIV.

The port of Antwerp, in conformity with the stipulations of the XVth Article of the Treaty of Paris, of the 30th of May, 1814, shall continue to be solely a port of commerce.

Article XV.

Works of public or private utility, such as canals, roads, or others of a similar nature, constructed wholly or in part at the expense of the Kingdom of the Netherlands, shall belong, together with the advantages and charges thereunto attached, to the country in which they are situated.

It is understood that the capitals borrowed for the construction of these works, and specifically charged thereupon, shall be comprised in the aforesaid charges, in so far as they may not yet have been repaid, and without giving rise to any claim on account of repayments already made.

Article XVI.

The sequestrations which may have been imposed in Belgium during the troubles, for political causes, on any property or hereditary estates whatsoever, shall be taken off without delay, and the enjoyment of the property and estates abovementioned shall be immediately restored to the lawful owners thereof.

Article XVII.

In the two countries of which the separation takes place in consequence of the present Articles, inhabitants and proprietors, if they wish to transfer their residence from one country to the other, shall, during two years, be at liberty to dispose of their property, movable or immovable, of whatever nature the same may be, to sell it, and to carry away the produce of the sale, either in money or in any other shape, without hindrance, and without the payment of any duties other than those which are now in force in the two countries upon changes and transfers.

It is understood that the collection of the droit d'aubaine et de detraction upon the persons and property of Dutch in Belgium, and of Belgians in Holland, is abandoned, both now and for the future.

Article XVIII.

The character of a subject of the two Governments, with regard to property, shall be acknowledged and maintained.

Article XIX.

The stipulations of Articles from XI to XXI, inclusive, of the Treaty concluded between Austria and Russia, on the 3rd of May, 1815, which forms an integral part of the General Act of the Congress of Vienna, stipulations relative to persons who possess property in both countries to the election of residence which they are required to make, to the rights which they shall exercise as subjects of either State, and to the relations of neighbourhood in properties cut by the frontiers, shall be applied to such proprietors, as well as to such properties, in Holland, in the Grand Duchy of Luxembourg, or in Belgium, as shall be found to come within the cases provided for by the aforesaid stipulations of the Acts of the Congress of Vienna. It is understood that mineral productions are comprised among the productions of the soil mentioned in Article XX of the Treaty of the 3rd of May, 1815, above referred to. The droits d'aubaine et de detraction being henceforth abolished, as between Holland, the Grand Duchy of Luxembourg, and Belgium, it is understood that such of the abovementioned stipulations as may relate to those duties shall be considered null and void in the three countries.

Article XX.

No person in the territories which change domination, shall be molested or disturbed in any manner whatever, on account of any part which he may have taken, directly or indirectly, in political events.

Article XXI.

The pensions and allowances of expectants, of persons unemployed or retired, shall in future be paid, on either side, to all those individuals entitled thereto, both civil and military, conformably to the laws in force previous to the 1st November, 1830.

It is agreed that the above-mentioned pensions and allowances to persons born in the territories which now constitute Belgium, shall remain at the charge of the Belgian treasury; and the pensions and allowances of persons born in the territories which now constitute the Kingdom of the Netherlands, shall be at the charge of the Netherland treasury.

Article XXII.

All claims of Belgian subjects upon any private establishments, such as the widows' fund, and the fund known under the denomination of the fonds des leges, and of the chest of civil and military retired allowances, shall be examined by the Mixed Commission mentioned in Article XIII, and shall be determined according to the tenour of the regulations by which these funds or chests are governed.

The securities furnished, as well as the payments made, by Belgian accountants, the judicial deposits and consignments, shall equally be restored to the parties entitled thereto, on the presentation of their proofs. If, under the head of what are called the French liquidations, any Belgian subjects should still be able to bring forward claims to be inscribed, such claims shall also be examined and settled by the said Commission.

Article XXIII.

All judgments given in civil and commercial matters, all acts of the civil power, and all acts executed before a notary or other public officer under the Belgian administration, in those parts of Limbourg and of the Grand Duchy of Luxembourg, of which His Majesty the King of the Netherlands, Grand Duke of Luxembourg, is to be replaced in possession, shall be maintained in force and validity.

Article XXIV.

Immediately after the exchange of the Ratifications of the Treaty to be concluded between the two parties, the necessary orders shall be transmitted to the commanders of the respective troops, for the evacuation of the territories, towns, fortresses, and places which change domination. The civil authorities thereof shall also, at the same time, receive the necessary orders for delivering over the said territories, towns, fortresses, and places to the commissioners who shall be appointed by both parties for this purpose.

This evacuation and delivery shall be effected so as to be completed in the space of fifteen days, or sooner if possible.

(L.S.) Palmerston. (L.S.) Senfft. (L.S.) H. Sebastiani. (L.S.) Bulow. (L.S.) Pozzo di Borgo. (L.S.) Sylvan van de Weyer.

References

Sanger, C. P. and H. T. J. Norton. England's Guarantee to Belgium and Luxemburg, with the Full Text of the Treaties. New York: Charles Scribner's Sons, 1915.