In the 12th and 13th centuries, Ladoga functioned as a trade outpost of the powerful Novgorod Republic. Later its trade significance declined and most of the population engaged in fishing in the 15th century. After new fortresses such as Oreshek and Korela were constructed in the 14th century further to the west of Ladoga, the town's military significance also decreased. Ladoga belonged to Vodskaya Pyatina of the Republic and contained eighty-four homesteads in the 15th century; most of the land belonged to the church. The Novgorodians built there a citadel with five towers and several churches.