of the 9th-10th centuries was divided in several units: three or four according to the sources, distinguished by their epithets and each, at least originally, under is respective .

The senior unit was the 'Great ' (u????? ????????, ), under the , who ranked as the senior of the military officials known as and was often referred to simply as 'the ' ? ???????????? par excellence. It was a very important position in the late 9th and first half of the 10th centuries, as he was in charge of the emperor's security, and was