St Louis (August 25) is the only canonised king of France

The only canonised king of France, Louis IX succeeded to the throne aged 12 after his father Louis VIII died, his mother Blanche of Castile assuming the rule of regent.

The king is chiefly remembered for his crusading, taking part in the Seventh Crusade (1248) in his mid-30s and then again joining the Eighth Crusade while in his 50s. The first of these began well but ended in predictably disastrous fashion.

Although Jerusalem had fallen to the Muslims in 1245, this caused less of a shock in Christendom than with previous conquests, the city having changed hands now so many times as to be less than earth-shattering.

Nevertheless France, having ended the Albigensian Crusade against Cathar heretics in the Languedoc, had resources, and in 1245 Louis, almost alone among Europe’s apathetic leaders, set sail to win back the Holy Land.

By late 1249, however, his army had been bogged down by the Nile, and the following year Louis was captured by the Egyptians and ransomed for 400,000 livres, a third of the kingdom’s annual revenue. After this he spent four years in Acre, Jaffa and elsewhere in the Crusader kingdoms, leaving not just a formidable Christian defence but a Francophone legacy that is still felt among the Maronites of Lebanon (cemented by the mandate of the 20th century).

Away from warfare he did much to promote the Gothic style of art and architecture that marks the triumph of medieval Europe, spreading Parisian artistic styles across the continent. Among his greatest legacies is La Sainte-Chapelle on the Isle de la Cité in Paris.

France was Europe’s pre-eminent state during this period and for this reason it is often called the “golden century of Saint Louis”. According to one contemporary, “The prestige and respect felt in Europe for King Louis IX were due more to the attraction that his benevolent personality created rather than to military domination” – although that certainly helped.

Famous for his sense of justice, he clamped down on nobles, including the Lord of Coucy who in 1256 was brought to trial for killing three young men, was refused trial by battle and forced to pay money for the Masses of the men he killed. Louis also made peace with the Count of Barcelona, thus helping to confirm the Spanish-French border as it remains today.

But his holiness went hand-in-hand with a zeal that today we find unpleasant. He cracked down on “usury”, by which was meant extorting money from the Jews (and Lombards), and he also expanded the power of the Inquisition against the Cathars, leading to an atmosphere of terror and suspicion in the south.

Zealous for the faith, in 1267 he, along with three sons, took the cross once more, and landed in Carthage, where disease broke out across the camp, taking the king away.