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Among the 27 men named in the preamble to Magna Carta as King John of England's advisors and negotiators was Alan, lord of Galloway and constable of the Scottish king, Alexander II. How had this man, ruler of semi-independent Galloway, a senior officer in Alexander's kingdom and lord of Lauderdale and Cunninghame, come to exercise such influence in English politics?

On 19 June 1215 by the Thames at Runnymede, King John agreed to Magna Carta - the Great Charter.

This iconic document, a foundation stone of the English and later British constitution, was a negotiated settlement between the king of England and his rebellious barons that was intended to address grievances arising from his ruthless exercise of power, manipulation of law, and exploitation of money-raising rights.

Produced in the context of a British Isles that still contained multiple independent realms, of which England was simply the largest and most powerful, it has often been presented as a purely English document designed to resolve a purely English conflict.

To see it thus, however, ignores the interconnectedness of the royal families and noble communities of the two principal powers in mainland Britain that was already long established at the beginning of the 13th Century and which is embedded into the content of Magna Carta itself - this quintessentially English document has distinctly Scottish dimensions.

In fact, among the charter's 63 clauses is Clause 59 which provides explicitly to do justice to the Scottish king in respect of "the sisters and hostages of Alexander, king of Scotland, his liberties and his rights".

Anglo-Scottish interrelationships

Why did such a clause appear in an agreement that otherwise focuses wholly on English domestic affairs and what did it mean?

The complexity of Anglo-Scottish interrelationships at this time are perhaps personified by Alan of Galloway.

Although usually seen as "Scottish", Alan possessed multiple identities; he had both Gaelic and "Anglo-Norman" heritage, descended from Galloway's independent kings, and linked to the ruling dynasties of the kingdom of Man and the Isles.

As a great-grandson of King Henry I of England he was John's "cousin" and held extensive properties in both England and English-dominated Ireland.

Image copyright AP Image caption The Lincoln Cathedral Magna Carta is one of four surviving examples of the 1215 parchment document out of 40 penned

As recently as 1212 he had provided galleys and warriors for King John's Irish wars.

He could thus appear to be a trusted kinsman and counsellor of the English king.

On the other hand, however, he was married to King Alexander's cousin (his grandson, John Balliol, became Scotland's king in 1292 through that link) and was related by marriage to several rebel barons. In that light, his role as one of John's counsellors is altogether more ambivalent.

Like his multiple identities, Alan's activities at Runnymede operated on multiple levels.

He was perhaps counselling John but he was also addressing Alexander II's and his own personal agendas.

Political crisis

Alexander's grievances which Clause 59 addressed were two-fold.

First, his inherited claim to the three northern counties of England which had been inherited by his father King William in 1152 but which John's father, Henry II, had taken back into English hands in 1157 despite promises to honour William's position.

Second, in 1209 John had taken possession of Alexander's two elder sisters with a promise to arrange their marriages, for which the Scots made a cash payment equivalent in modern values to tens of millions of pounds.

Despite regular promises to 'do right' in respect of both of these issues, John had consistently failed on both counts.

England's political crisis thus gave Alexander an opportunity to realise long-cherished dreams and to right what, in his eyes, were deep injustices.

In addition to having personal grievances against John, Alexander was brother-in-law of one of the rebel leaders.

The barons hoped to use these factors to draw Alexander into the conflict on their side.

Image copyright Getty Images Image caption A 1297 copy of Magna Carta, bearing the seal of Edward I

Alexander and his advisors, however, preferred to use the threat of military intervention rather than actual commitment as a lever to force John into negotiations and insert one of the Scottish king's key advisors - whose office as constable represented the leadership of Scotland's military forces - into John's negotiating team.

This position also allowed Alan to pursue his own inherited claims in the northern English counties which had been held by his mother's Anglo-Norman forebears, the Morville family, but which had also been lost in 1157.

Recognition of Alexander's rights would result in the restoration of Alan's claims to North Westmorland and other English lordships.

Clause 59 of Magna Carta was, therefore, the fruits of Alan of Galloway's participation in the Runnymede negotiations.

He had not won the immediate granting of everything that Alexander or he wanted but he had extracted a legal concession that justice would be done, and that, after John's years of evasion, was a major gain with which both king and constable could be well satisfied.

Their satisfaction was, of course, short-lived for John's representatives swiftly appealed to Pope Innocent III to have the agreement annulled.

Pope Innocent agreed.

John's opponents were excommunicated and in September 1215 he received Innocent's formal annulment.

Civil war erupted in England, this time with the Scots supporting the rebels and invading the disputed northern counties.

Image copyright Thinkstock Image caption The Magna Carta memorial at Runnymede

Alexander even rode to Dover to meet the rebel leaders.

John's death in October 1216 saw a rapid reversal of the rebels' fortunes as the English barons began to rally around the blameless figure of John's nine-year-old son, Henry III.

The child-king's advisors cannily re-granted Magna Carta, but this time shorn of Clause 59.

Alexander had no option but to fight to retain the three counties, with Alan of Galloway holding Carlisle in his name, but when the English rebels surrendered in September 1217 they had no option but to seek terms.

Runnymede had presented a momentary opportunity to secure a lasting settlement of a long-running source of Anglo-Scottish conflict.

John's duplicity snatched away that chance, precipitated a war, and brought another 20 years of often tense relations before Alexander II and Henry III at last reached a compromise which resolved the issues which Magna Carta had promised to address.

Richard Oram is Professor of Medieval and Environmental History at the University of Stirling