originally Espå / Espåå), which in turn is thought to have come from the aspen trees on the shores of the river (the Swedish word for "aspen" is äspe). The name was first mentioned in 1431. Originally, the current river Gumbölenjoki was renamed Espoonjoki after the village located along the river. When a church was founded near the village of Södrik, the name Espoonjoki was given to a river running from lake Kirkkojärvi to Kauklahti. Espoo became an independent parish in the 15th century. Previously Espoo had been a chapel parish under Kirkkonummi. The stone Espoo Cathedral was built in the 1480s by initiative from the peasants. Up to the 1670s the eastern parts of Espoo belonged to the Helsinki parish, after which they were officially annexed to the Espoo parish and the slottslän of Raseborg. After the Second Crusade to Finland, settlers from Sweden established permanent agricultural settlements in Uusimaa. Espoo was a subdivision of the Kirkkonummi congregation until 1486–1487. The oldest known document referring to Kirkkonummi is from 1330; Espoo as a subchapter has been dated to the 1380s, although the first document directly referring to Espoo is from as late as 1431. The construction of the Espoo Cathedral, the oldest preserved building in Espoo, marks the independence of Espoo. Administratively, Espoo was a part of Uusimaa. When the province was split to Eastern and Western provinces governed from the Porvoo and Raseborg castles, respectively, the eastern border of the Raseborg province was in Espoo. The 13th-century road connecting the most important cities in Finland at that time, the King's Road, passes through Espoo on its way from Stockholm via Turku and Porvoo to Viipuri. Gräsa manor The oldest frälse stead in Espoo, the Gräsa manor, apparently received frälse rights in the late 15th century. Gräsa is one of the oldest settlements in Espoo and the oldest in southern Espoo, as it was probably founded already in the early 14th century as Swedish settlement moved inland. From the beginning, the settlement was located at the site of the current Olari Church on both sides of the Gräsanoja river. The absence of Finnish names in the area reveals that the population was Swedish-speaking from the beginning. Early modern period In 1556, King Gustav Vasa decided to stabilize and develop the region by founding a royal mansion in Espoo. The government bought the villages of Espåby and Mankby (Finnish: Mankki)