Timeline on Thailand’s political crisis

Six months of political unrest in Thailand prompted the military to declare martial law on Tuesday. Here's a summary of how the crisis has been building up.

The Thai army’s declaration of martial law on Tuesday was to quell six months of unrest that has its roots in the 2006 ouster of the tycoon-turned-premier Thaksin Shinawatra, now in self-imposed exile to avoid jail for a corruption conviction.

October 31, 2013 Protests break out after the government, led by Mr Thaksin's sister Yingluck Shinawatra, proposes an amnesty bill that critics say is aimed at allowing him to return home without facing jail time

November 1 The lower house of parliament, which is dominated by the ruling party, passes the bill

November 11 Amid growing outrage on the streets, the upper house overwhelmingly rejects the legislation

November 25 Opposition supporters march on state buildings, eventually occupying several ministries

November 30 Opposition demonstrators attack a bus carrying government supporters. Several people are killed and dozens wounded in street violence

December 8 Opposition MPs resign en masse from parliament

December 9 Ms Yingluck calls early elections. Opposition later announces boycott

December 22 Protesters stage massive anti-government rally in Bangkok

December 26 The government rejects a call from the election commission to postpone the ballot after violent clashes

December 27 The army chief refuses to rule out a coup, saying "anything can happen"

December 28 A gunman kills a protester and wounds several others, triggering a series of drive-by shootings at demonstrators

January 13, 2014 Tens of thousands of protesters occupy major streets in an attempt to "shut down" Bangkok

January 16 Anti-corruption authorities probe possible negligence of duty by Ms Yingluck over a controversial rice subsidy scheme.

January 17 A grenade leaves one dead and dozens wounded at an opposition march, the first of several blasts targeting the rallies

January 21 Government declares a 60-day state of emergency in Bangkok and surrounding areas

January 26 A protest leader is shot dead while giving a speech, as fellow demonstrators disrupt advance voting for the election

February 2 Demonstrators prevent 10,000 polling stations from opening for the election, affecting several million voters

February 11 The election commission schedules election re-runs on April 27 in constituencies where voting was obstructed

February 14 Riot police are deployed in Bangkok to reclaim government buildings surrounded by demonstrators

February 19 A court bans use of force against protesters, a day after five are killed in clashes during a police operation to dislodge them

March 1 Demonstrators lift blockade of Bangko.

March 18 State of emergency lifted in Bangkok

March 21 Constitutional court annuls February elections

April 30 Government announces new elections for July 20

May 7 Constitutional court removes Ms Yingluck and several cabinet ministers from office. Niwattumrong Boonsongpaisan appointed caretaker premier by remainder of cabinet

May 9 Protesters call for the senate to aid their bid to topple the government

May 10 Pro-government protesters warn of "civil war" if an unelected leadership takes power

May 15 The election commission says a general election scheduled for July 20 is "no longer possible" as polls cannot be held without the support of the protesters.

Army chief General Prayuth Chan-ocha warns his troops “may use force” to quell political violence after three people are killed in an attack on anti-government protesters in Bangkok.

May 20 Army declares martial law, stresses the move "is not a coup" and that there is no need for public panic

* Agence France-Presse