Libyan ruler Moammar Gadhafi is the Arab world's longest-serving leader since coming to power in a 1969 military coup that overthrew King Idriss.
Colonel Gadhafi said Libya was a "Jamahiriya" - Arabic for a republic of the masses - but he was also known to quash dissent and is reported to have survived several assassination attempts.
The Libyan regime led a 1973 invasion of neighboring Chad, and has long been reported to support Islamic militant groups.
The African nation became an international pariah after a Libyan agent in 1988 placed a bomb on a Pan Am flight that exploded over Lockerbie, Scotland, killing 270 people.
Lately, Colonel Gadhafi has tried to soften his image. In 1999, he agreed to send two Libyans to stand trial for the Lockerbie bombing. He has also helped broker the release of European hostages in the Philippines and in Algeria.