The Castle (Osma)

X, XI and XVIII centuries The fortress is located on top of a rocky massif that separates the Abión and Ucero riverbeds and is separated by a hill from the moors that border the Duero valleys to the south. In 912 the village of Osma is documented and although it could be thought to be a repopulation of the ruins of the Roman city of Uxama, there is evidence of structures on the hill of the current castle that would allow locating this initial village there. Around 933, when the first defeat of the Caliphate troops took place in Osma or in 934 when Ramiro II of León and Count Fernán González took refuge in the castle (there are doubts whether in this or in that of Gormaz), most of the fortress that we see today must have been built by the Leonese. The strategic importance of the castle of Osma increases decidedly after the Muslim defeat of 939, in the continuation of the battle of Simancas, to the south of Gormaz. The Caliphate reacted in the following years by recovering Gormaz and fortifying it. Thus for fifty years (between 934 and 989) the castle of Osma was the main defense of the gates of the kingdom of León in this section of the Duero and undoubtedly the Christian castle most exposed to the attack of the terrible Muslim enemy. The work of Ramiro II of León was attached to the previous towers and was made of thick masonry with an abundance of Roman stones and superb ashlars carved with stonework marks in corners, doors and arrow slits. The high castle had four towers (the two pre-existing ones and the two new ones, one of them pentagonal and hollow) and two gates, to the north and south, that allowed to go down towards the rivers Abión and Ucero. Fifty years resisting against the Caliphate and the formidable fortress of Gormaz is a long time but in the end, Almanzor was Almanzor, and Osma fell into his hands in 989. In 994 San Esteban and Clunia fell and the following year the Castilian count Garci Fernandez lost his head in Alcozar. The famous general from Algeciras repopulated with Arabs and refortified the castle of Osma and part of the exterior plating of the tower overlooking Uxama could be his, remaining in the power of the Caliphate until 1011 when it passed back into Christian hands.