ipsius
ipsius is a Latin form of ipse, meaning “self, himself, herself; the very”. It is the genitive singular masculine pronoun.
Found 854 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 1.21.1: Eodem die ab exploratoribus certior factus hostes sub monte consedisse milia passuum ab ipsius castris octo, qualis esset natura montis et qualis in circuitu ascensus qui cognoscerent misit.
Vergil, Aeneid 5.535: Ipsius Anchisae longaevi hoc munus habebis,
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.