Veliko Tarnovo was the seat of Royal power in the 14th century. The fortress contained both the Royal Palace and as the seat of the Patriarch of Bulgaria. Though seemingly impregnable the fortress fell to the Ottomans in 1393. The Bulgarians revolted many times until 1875 when the infamous 'Bulgarian Massacres' led to Russian intervention in 1877. Under the terms of the Treaty of San Stefano Bulgaria became an independent state but with a new capital Sofia.