He served as an Exilarch during the days of Samuel of Nehardea, who was also his Rabbi, but at the same time, Samuel was subordinated to Mar Ukva in Ukva's capacity as "Av Beit Din" (chief of the rabbinical court) and its second-highest-ranking member.
He resided at Kafri city, Babylonia, about 20 km south of Sura,[4] where his rabbinical court was also located.
He was very strict about refusing any action that could be interpret as a bribe to him by one of the parties in a case.
[7] In the Talmud it is said that he was a righteous man and used to give tzedakah anonymously, in order not to shame the needy he handed the charity to.
When Mar Ukva died he left behind orphan children, and Samuel of Nehardea became their guardian.