On 14 August 1385 in Kreva Castle, Jogaila confirmed his prenuptial promises in the Union of Krewo (Union of Kreva). The promises included the adoption of Christianity, repatriation of lands "stolen" from Poland by its neighbours, and "terras suas Lithuaniae et Russiae Coronae Regni Poloniae perpetuo applicare", a clause interpreted by historians to mean anything from a personal union between Lithuania and Poland to a complete incorporation of Lithuania into Poland. The agreement at Kreva has been described both as far-sighted and as a desperate gamble.