The boat collision is once again bringing attention to the Diaoyu Islands issue. The Diaoyu islands have a long history as part of China's territory, belonging to the country since ancient times.
The islands are 200 nautical miles east of China's mainland and 200 nautical miles west of Japan's southernmost island Okinawa.
China's claim over the Diaoyu Islands dates back to the early 15th century. The Imperial Map of the Ming Dynasty included them as part of Ming Empire's territory.
After the Ming Dynasty, documents show the islands remained as part of China.
That was until 1895, when Japan forced China to give up Taiwan and the islands surrounding it to Japan, the Diaoyu islands included.
After World War II, international documents recognized Taiwan and the islands around it as falling under Chinese territory. But the administration of the islands fell into Japanese hands in 1972.
Also in the 1970's, large reservoirs of oil were discovered under the continental shelf below the Diaoyu Islands. This increased the tension between China and Japan over the islands.
Over the past decades, protesters from the Chinese Mainland, Hong Kong and Taiwan made repeated efforts to declare China's sovereignty over the Diaoyu Islands.
In March 2004, seven Chinese activists landed on the Diaoyu Islands as a gesture of protest and were arrested by the Japanese for illegal entry.
In 2008, the Taiwan fishing boat Lien Ho was sunk by a Japanese frigate. The Taiwan authority and public protested strongly.
Other border conflicts include Japan's complaint about China's routine naval drill in the East China Sea in April 2010.