[5] Ivan first appears as one of Jogaila's boyars during the truce between Lithuanian princes and the Prussian branch of the Teutonic Order in 1379.
[3][7] After Vytautas gained a powerful ally in the east, Jogaila agreed to make peace and Treaty of Astravas was signed in 1392.
On 12 February 1401 in Merkinė he swore allegiance to Jogaila (King Władysław), and the Polish Crown in the event of the death of Grand Duke Vytautas.
[11] His father Algimantas (Polish: Olgimunt) was baptised in the Orthodox faith under the name of Michael, during his rite of tonsure he received the name of Euthymius.
[5] They had four sons: Andrew, Semen, Aleksander and Michael, and daughter Uliana, married first to Prince of Karachev later to Grand Duke Vytautas.