The Indonesian government and the Free Aceh Movement (GAM) signed in Finland's capital Helsinki a peace agreement on Monday.
Following are some key facts about the Aceh issue.
The province of Aceh is located on the northern tip of Sumatra. About 98 percent of the 4 million population is Muslim, compared with about 85 percent for the country as a whole.
The province is rich in oil, natural gas, gold, silver, timber and rubber.
Gerakan Aceh Merdeka, or the Free Aceh Movement in English, has fought for independence from Indonesia since 1976. About 12,000 people are estimated to have been killed in the conflict.
GAM considers Prince Hasan di Tiro the rightful head of state of Aceh and Malik Mahmud its prime minister. The GAM leadership fled to asylum in Sweden after declaring independence from Indonesia nearly 30 years ago.
In 1999 when President Abdurrahman Wahid took office, the Indonesian government agreed to Aceh autonomy, but refused to accept an independent Aceh.
Meanwhile, the government and GAM began peace talks.
However, the negotiations collapsed in May 2003 in Tokyo with each party complaining about the other's interpretation of a December 2002 truce. The Indonesian military soon launched an offensive to crush GAM and imposed martial law, which was later replaced by a state of civil emergency.
According to official statistics, after a year-long military operation, the Indonesian government resumed control of the province.
Both sides were ready to talk peace after the province took the brunt of the Dec. 26 tsunami, in which nearly 168,000 people in Aceh were left dead or missing.
During talks in February, GAM proposed "self government" in return for dropping its fight for Acehnese independence. GAM has agreed to drop the demand as long as Jakarta let its representatives run in local elections as an official Aceh-based party.
On July 16, the Indonesian government and Aceh rebels reached a ground-breaking tentative agreement on ending their 30-year-old conflict and plan to formally sign a truce on Aug. 15.