 Complete the following phrase:  The final attempt to Christianize Lithuania was made by Jogaila. Jogailas Russian mother urged him to marry Sofia, daughter of Prince Dmitri of Moscow, who required him first to convert to Orthodoxy and to make Lithuania a fief of the Grand Duchy of Moscow. That option, however, was unrealistic and unlikely to halt the crusades against Lithuania by the Teutonic Order. Jogaila chose therefore to accept a Polish proposal to become a Catholic and marry Queen Jadwiga of Poland. On these and other terms, on 14 August 1385, at the castle of Krėva, Jogaila agreed to adopt Christianity, signing the 