False hopes of a Muslim emir’s conversion helped trigger Louis IX’s fatal Tunis crusade

Evidence

It was probably such false hopes that led Louis IX into the fatal debacle of his second Crusade, against Tunis. In 1269 Dominican Ramon Martí came to Paris; preparations were under way for a fresh Crusade involving both Louis and Jaume I of Aragon. Martí then was sent to Tunis (probably from November 1269 to March 1270) where he attempted to convert the Tunisian emir al-Mustansir, who had at one point, it seems, suggested that he might be willing to convert. Louis set out in the spring of 1270 and landed near Tunis, apparently with the hopes of securing the conversion and allegiance of al-Mustansir. He soon found out that the promise of conversion was not to be kept, and he laid siege to the city, only to die soon after. — John V. Tolan, Saracens, 1042

It was probably such false hopes that led Louis IX into the fatal debacle of his second Crusade, against Tunis. … Louis set out in the spring of 1270 and landed near Tunis, apparently with the hopes of securing the conversion and allegiance of al-Mustansir. He soon found out that the promise of conversion was not to be kept, and he laid siege to the city, only to die soon after. — John V. Tolan, Saracens, 1042

Categorization

• QUESTION: How credible was al-Mustansir’s suggestion of conversion, and did diplomats misread diplomatic politeness as genuine religious interest?
• corroborated: 2 independent passages support this claim — John V. Tolan, Saracens, 1042