Ukmerge is a city in Vilnius County, Lithuania, located 78 km (48 mi) northwest of Vilnius, with a population of about 26,000 (2011). The region began to adopt Christianity, along with the rest of Lithuania, in 1386. In the following year, 1387, its first Catholic church, St. Peter and St. Paul, was built. It was one of the first Roman Catholic churches established in Lithuania. The town was granted municipal rights at some time after the Battle of Pabaiskas in 1435, and written sources dating from 1486 referred to it as a city. King Sigismund the Old confirmed these rights. During the times of the Polish–Lithuanian Commonwealth, the city had been the center of powiat in the Vilnius Voivodeship.