Ulrich also received the inheritance of the respected family Cirksena through his mother Gela, daughter of Affo Beninga, headling of Pilsum and Manslagt, and Tiadeka Siartze of Berum.

When Edzard and Frauwa died childless in 1441 from the plague, Ulrich inherited the holdings of the Cirksenas of Berum as well.

In 1430, together with his father and eldest stepbrother Edzard, Ulrich concluded the Freiheitsbund der Sieben Ostfrieslande (Freedom-alliance of the seven East Frisian lands).

After Ulrich Cirksena's marriage to Theda, granddaughter of his opponent, in 1455, the majority of the East Frisian lands were united for the first time.

Sibet Attena, a nephew and ally of Ulrich, received the Lordships of Esens, Stedesdorf and Wittmund, which together formed the Harlingerland.