South Korea is renaming peaks on islands disputed with Japan in an attempt to reassert its sovereignty over the territory after a decades-long dispute flared up again this summer. The row over the Seoul-controlled islands - called Dokdo in South Korea and Takeshima in Japan - boiled over in August when South Korean President Lee Myung-bak made a surprise visit to them. Tokyo said the trip to the islands, the first ever by a South Korean president, was deliberately provocative. The islets are in the Sea of Japan, known to Koreans as the East Sea. One of the two peaks will be named Usan after its ancient title dating back to the Joseon dynasty that ruled Korea from 1392 to 1910, the land ministry said. The other will be named Daehan, South Korea's official name in Korean. The peaks were previously called the East and the West hills. "The move is aimed at firmly asserting our territorial sovereignty over Dokdo," said the ministry. School textbooks, official maps and internet websites would use the new names beginning today, it said. The recent flare-up prompted Seoul to lash out at Google after the US online search engine changed the name of the islands on its web mapping service. Google recently updated its Google Maps and - on the English-language version - replaced the name of Dokdo with Liancourt Rocks, a name taken from a French whaling ship that came close to being wrecked on the islets in 1849. The South's foreign ministry called the move unacceptable and protested to Google against the change.