Complex sentence: Alexios Komnenos (ca.1135--after 1182) was a Byzantine aristocrat and courtier, bearing the ranks of "prōtostratōr" in 1170 and eventually "prōtovestiarios".
Split into simpler sentences: Alexios Komnenos (ca.1135--after 1182) was a Byzantine aristocrat and courtier. He rose to the ranks of "prōtostratōr" (in 1170) and eventually "prōtovestiarios".