The Battle of Valdejunquera was a victory for the Islamic Emirate of Córdoba over the Christian armies of the kingdoms of León and Navarre that took place in a valley called Iuncaria (Junquera) in 920 as part of the Córdoban "Campaign of Muez" (Campaña de Muez), which was directed primarily against the southern line of defences of the County of Castile along the Duero. The earliest reference to the battle is found in the Chronicon of Sampiro, a Leonese cleric, written probably in the late 980s.