Osraige, (pronunciation) also known as
Osraighe or
Ossory (modern ), was a medieval Irish kingdom comprising most of present-day
County Kilkenny and western
County Laois. The home of the Osraige people, it existed from around the first century until the
Norman invasion of Ireland in the 12th century. It was ruled by the
Dál Birn dynasts, whose medieval descendants assumed the name
Mac Giolla Phádraig. The name survives in the Catholic
Diocese of Ossory, established in the 5th century, which continues to use roughly the same borders.