ألفونسو السادس ملك قشتالة
Professor Ubieto Arteta reported that there is some historical evidence of Cuéllar's existence in the 10th century. Al-Mansur Ibn Abi Aamir (Spanish name: Almanzor) sacked the town and enslaved and deported its citizens to Andalusia. King Alfonso VI of León and Castile rebuilt the town, bringing in new settlers at the end of the 11th century. This was the origin of the municipality, which was ruled by its town council. In 1184, King Alfonso VIII of Castile assembled the parliament in Cuéllar.