Oliver was born into the prestigious and influential gens (clan) Rátót, as the son of Dominic I, who was killed in the Battle of Mohi in 1241.
Oliver had three brothers, Roland I, Stephen I and Leustach II, and a sister, who married Maurice Pok.
He served as treasurer of Queen Maria Laskarina's court from 1262 to 1268,[2] but it is plausible he held the dignity until 1270, Béla's death.
[4] Despite he supported Béla IV in the civil war against his son Duke Stephen, Oliver retained his positions in the royal court, when the latter ascended the Hungarian throne in 1270.
He lost the office still in that year,[5] and was ousted from politics thereafter, when rivaling baronial groups fought each other for the supreme power during the minority of Ladislaus IV of Hungary.