As king, Henry Tudor was heavily involved in the Potassium Alum trade, a participation through which he accumulated a large part of his great wealth. Potassium Alum was one of Europe’s most precious commodities and was coveted for its medicinal and cosmetic properties, particularly its usage in the 15th and 16th century as a dye-fixer in the wool and cloth trade upon which a large part of the English and Low Country economy was built. To say it was an indispensable mineral to the continuation of the English economy is an understatement to say the least. Alum was plentiful in the Eastern Mediterranean region which was under the control of Turkish Muslims whereas in Western Europe there was only one source and that was the Papal-owned mine at Tolfa, near Rome. The Papacy determined to ensure maximum profits from this source and therefore attempted to restrict the supply and therefore raise prices; in short they created a monopoly on Alum in Christian Europe and threatened excommunication and anathema on anybody who traded with the ‘infidel’, that is, the Muslim East.

In 1503 Pope Julius II endeavoured to once more raise prices which caused an economic slump in the Low Countries and forced the Habsburgs Maximilian and Philip to flout Papal decrees and deal with the Muslims. Maximilian was Holy Roman Emperor and as such it was not possible for him to openly disobey a papal edict therefore it was decided to go via England, and Henry VII. The King loaned his great ships Sovereign and Regent to the scheme which was undertaken by the Frescobaldi bank of Italy and they sailed to the Ottoman Empire to bring back Alum to England. From here Henry’s own broker Ludovico della Fava, who was also a representative of the Frescobaldi Bank, brokered deals to sell the mineral onto the Low Countries. Henry claimed money not only from the Alum itself, but also on huge import charges and customs duties, helpfully arranged by Edmund Dudley. In one single occasion a ship brokered by Henry, Dudley and della Fava brought in £15,166 which in modern estimates is around £10m.

In May 1506 the Pope was forced to issue a papal proclamation forbidding the involvement of all persons secular and ecclesiastical from trading with any alum that didn’t come directly from the Papal mine at Tolfa. Julius amusingly declared that his Alum, rather than being for mere profit, was ‘reserved and consecrated to the preparations for a great crusade against the Sultan of Constantinople’. Henry was unmoved by such threats of anathema and possible excommunication despite his genuine enthusiasm for the idea of a crusade in defence of the church. He loved the church but he additionally loved making a profit and saw no reason that he would need to compromise one for the other.

Through his involvement in the alum trade, Henry retained his position at the heart of European power politics through his financial supremacy over his militarily-superior rivals. Ever the consummate schemer, as always Henry demonstrated an economic wisdom that enabled the continued resurgence of his kingdom.