In 1336 Bartholomaus went with his brother Stephen into the solitude of Radonezh. At the age of 23, he founded the Trinity Monastery (Zagorsk), known as Sergiy of Radonezh. Sergij also introduced many reforms of monastic life. The 14th century was virtually predestined for this, as at that time the connection between ecclesiastical and secular power in the rising Moscow was solidified. For example, Alexander Nevsky’s grandson, Ivan I, also known as the Money Bag (Kalita), had the Koimesis Cathedral, Moscow’s first stone church, built in a one-year construction period, which was once due to the instigation of Metropolitan Petr, and on the other hand to the relocation of the Metropolitan Seat to Moscow in 1326. lwan Kalita, who had held the rank of Grand Duke since 1328, built the Kremlin from wooden buildings as early as 1329. Two major fires destroyed the plant again, but construction began again in 1339. Ivan I Kalita, Furst of Moscow, died in 1340. Sergius of Radonezh was involved in 40 monastic foundations and was already highly revered during his lifetime. Sergius once prayed in front of the icon of our Lady. After he had performed the prayer, a voice shot: “The All-Clean is coming.” Sergius stood up and stepped out of his cell. Then a great light poured out, in which the Mother of God stood, next to her the two apostles Peter and John. Mary said, “Do not be afraid”, and the light disappeared.