Tallinn is the capital, primate and the most populous city of Estonia. Located in the northern part of the country, on the shore of the Gulf of Finland of the Baltic Sea, it has a population of 434,562. Administratively a part of Harju maakond (county), Tallinn is the main financial, industrial, cultural, educational and research centre of Estonia. Tallinn is located 80 kilometres (50 mi) south of Helsinki, Finland, 320 kilometres (200 mi) west of Saint Petersburg, Russia, 300 kilometres (190 mi) north of Riga, Latvia, and 380 kilometres (240 mi) east of Stockholm, Sweden. It has close historical ties with these four cities. From the 13th century until the first half of the 20th century Tallinn was known in most of the world by its historical German name Reval.