The Siege of Bayonne was launched by Alfonso the Battler, King of Aragon and Navarre, apparently against the Duke of Aquitaine, William X, and lasted from October 1130 to October 1131. The city of Bayonne was then a part of Aquitaine, nominally a part of France. The chief narrative source for the siege of Bayonne is the Chronica Adefonsi imperatoris, a contemporary account of events in Spain compiled to celebrate the feats of Alfonso VII of León and Castile. The siege began with knights, infantry, and siege engines and included the plundering of the environs of the city and assaults on its walls. The arrival of a relief army led to a famous joust and the prolongation of the siege.