Drenther Crusade

[1] The incident which turned the conflict into a crusade was the killing of Bishop Otto II of Utrecht in the Battle of Ane in 1227.

[1] Willibrand received papal authorization for a crusade on the grounds, it appears, that the Drenthers were heretics for defying their bishop.

The County of Drenthe was a fief of the Holy Roman Empire belonging to the secular jurisdiction of the bishops of Utrecht.

F. H. J. Dieperink, on the other hand, has argued that they were mostly just opposed to compulsory payment of tithes and the governmental (not lordly) authority of the bishop.

[6] In late 1225 or early 1226, shortly after the assassination of Archbishop Engelbert II of Cologne, Count Rudolph of Coevorden with an army of Drenthers invaded Groningen, taking advantage of a dispute between the burgrave Egbert and his relatives, the wealthy Gelkingen.

Rudolph considered it a provocation, but Egbert defended his right to build whatever fortifications he wished within his own jurisdiction.

The Drenthers nonetheless attacked Glimmen, razed the defences and took many prisoners, forcing Egbert to retreat into Frisia.

The author of the Deeds of the Bishops, recognizing that at Ane a new and more intense phase of the fighting had begun, wrote that "it was here that the war began" (bellum hinc inde incipitur).

[2][9] Willibrand was at the imperial court in Italy at the time of his election and may have used the opportunity to obtain authorization from the pope for a crusade against the Drenthers.

[8][9] The charge against the Drenthers was almost certainly that they were heretics for defying their bishop's authority (contemptus clavium, contempt for the keys of the kingdom).

[10] Although King Henry (VII) of Germany declared the Drenthers outlaws after the battle of Ane, no royal or imperial aid was forthcoming to the bishops of Utrecht.

[4] When Rudolph's brothers continued the rebellion, Willibrand called on the Frisians and the townspeople of Groningen to support him in suppressing the rebellious Drenthers.

The Drenthean captain Hendrik van Borculo, who had recruited fresh troops in Westphalia, was able to repel another Frisian party that attacked the Drenthers at the Mitspete keep.