The Battle of Uclés is fought on May 29, 1108, near Uclés just south of the river Tagus between the Christian forces of Castile and León under Alfonso VI and the forces of the Muslim Almoravids under Tamim ibn-Yusuf.

The battle is a disaster for the Christians and many of the high nobility of León, including seven counts, die in the fray or are beheaded afterwards, while the heir-apparent, Sancho Alfónsez, is murdered by villagers while trying to flee.

Despite this, the Almoravids cannot capitalize on their success in the open field by taking Toledo.