A unified Thai kingdom was established in the mid-14th century. Known as Siam until 1939, Thailand is the only Southeast Asian country never to have been taken over by a European power. A bloodless revolution in 1932 led to a constitutional monarchy. In alliance with Japan during World War II, Thailand became a US treaty ally following the conflict. A military coup in September 2006 ousted then Prime Minister THAKSIN Chinnawat. The interim government held elections in December 2007 that saw the former pro-THAKSIN People's Power Party (PPP) emerge at the head of a coalition government. The anti-THAKSIN People's Alliance for Democracy (PAD) in May 2008 began street demonstrations against the new government, eventually occupying the prime minister's office in August and Bangkok's two international airports in November. The PAD ended their protests in early December 2008 following a court ruling that dissolved the ruling PPP and two other coalition parties for election violations. The Democrat Party then formed a new coalition government and ABHISIT Wetchachiwa became prime minister. In October 2008 THAKSIN went into voluntary exile to avoid imprisonment for a corruption conviction, and has since agitated his followers from abroad. THAKSIN supporters re-organized into the United Front for Democracy Against Dictatorship (UDD) and rioted in April 2009, shutting down an ASEAN meeting in Phuket, and in early 2010 protested a court verdict confiscating most of THAKSIN's wealth. Between March and May 2010, the UDD staged large protests and occupied several blocks of downtown Bangkok. A government operation to disperse the protesters after nine weeks led to clashes that resulted in 89 deaths and an estimated $1.5 billion in arson-related property losses. These protests exposed major cleavages in the Thai body politic which continue to hamper the current government. Since January 2004, thousands have been killed as separatists in Thailand's southern ethnic Malay-Muslim provinces increased the violence associated with their cause.