Manuel Zelaya came to power in January 2006
Honduran President Manuel Zelaya was sent into exile on 28 June amid a power struggle over his plans for constitutional change, triggering the biggest political crisis in Central America in years.
He returned covertly on 21 September and sought refuge in the Brazilian embassy.
Presidential elections on 29 November brought to power Mr Zelaya's centre-right rival Porfirio Lobo, but the ousted president and most Latin American countries have opposed the vote.
What exactly happened?
At dawn on 28 June, between 200 and 300 troops came to Mr Zelaya's home, and, in his own words, told him to surrender or they would shoot him.
He was driven to the airport and put on a flight to Costa Rica. Later the same day, the speaker of Congress, Roberto Micheletti, constitutionally second-in-line to the presidency, was sworn in as interim leader.
What provoked Mr Zelaya's removal?
Mr Zelaya planned to hold a non-binding public consultation on 28 June to ask people whether they supported moves to change the constitution.
Had voters supported it, a referendum on setting up a body charged with redrawing the constitution would probably have been held at the same time as November's presidential election.
Mr Zelaya's critics said the move was aimed at removing the current one-term limit on serving as president, and paving the way for his possible re-election.
Mr Zelaya has repeatedly denied he was seeking re-election. Some commentators point out the timescale also rendered this impossible. A constituent assembly would have had to be set up and would have needed to rewrite the constitution before Mr Zelaya's term expired in January 2010. In any case, by that time the country would have a new president-elect.
The consultation was ruled illegal by the Supreme Court and Congress, and was opposed by the army.
Was his removal a surprise?
To a certain degree, yes. Coups and political upheaval were common in Central America for much of the 20th Century, and until the mid-1980s the military dominated political life in Honduras.
Tension had been brewing in Honduras over the months leading up to Mr Zelaya's removal. He sacked the head of the armed forces, who refused to give logistical support for the 28 June vote. The Supreme Court overruled him, saying the army chief should be reinstated.
When Mr Zelaya insisted the consultation would go ahead, Congress voted to remove him for what it called "repeated violations of the constitution and the law", and the Supreme Court said it had ordered the president to be removed from office to protect law and order.
But why were relations between the president and the other institutions so strained?
Honduras is a poor country beset by corruption, with a huge wealth gap and widespread gang violence. However, it had been politically stable since the 1980s.
But Mr Zelaya, who came to office in 2006, had been moving the country steadily leftwards, enjoying the support of Venezuelan President Hugo Chavez and other left-wing leaders in the region.
This appears to have alarmed certain sectors in Honduras, who decried his plans for constitutional change as an attempt to stay in power.
For his part, Mr Zelaya argued that the 28 June vote would merely have been a survey: a canvassing of public opinion, not a legally-binding election.
What was the reaction in Honduras?
Since Mr Zelaya's removal, there have been demonstrations both for and against him.
On 5 July Mr Zelaya tried to fly back home, but his plane was blocked from landing.
Clashes between troops loyal to the interim government and Zelaya supporters left at least one person dead.
On 25 July Mr Zelaya made a brief but symbolic crossing into Honduras across its border with Nicaragua, where he was living in exile.
Two months later, on 21 September, he returned to Honduras, appearing in the Brazilian embassy in Tegucigalpa. He said had returned "for the restoration of democracy".
What was the international reaction to Mr Zelaya's removal?
International condemnation was swift and near-unanimous, as countries moved to isolate the interim leadership.
The Organization of American States demanded Mr Zelaya's immediate reinstatement.
A number of countries in Latin America, including Mr Zelaya's allies Bolivia, Ecuador and Venezuela, withdrew their ambassadors. All EU countries pulled out their diplomats. Brazil suspended visa-free travel for Hondurans.
The World Bank suspended financial aid.
What about the reaction from Washington?
The role of the US is key, as it is Honduras's biggest trading partner.
The Obama administration has adopted a careful tone, stressing that Mr Zelaya is the democratically-elected president but also that the crisis needs to be resolved peacefully through dialogue between the two sides.
In September, the US halted all non-humanitarian aid to the country, saying the interim government had failed to respect democratic processes.
But the US ambassador to the OAS, Lewis Amselem, said Mr Zelaya's return to Honduras before a settlement had been reached was "irresponsible and foolish".
What about diplomatic efforts to resolve the crisis?
After protracted negotiations, Mr Micheletti and Mr Zelaya reached a deal on 29 October that provided for a unity government.
Pressure from the United States is thought to have been significant, and Costa Rican President Oscar Arias has also been a pivotal mediator.
The deal required both sides to recognise the result of a 29 November presidential election and would transfer control of the army to the top electoral court.
It called on the international community to lift all sanctions, recognise the elections and send international election observers to oversee the polls.
However, as a 5 November deadline for the deal to be put into effect passed, Mr Micheletti said Mr Zelaya had not submitted any representatives for the new cabinet.
He said he was naming the cabinet anyway, adding that it would be representative of a wide political spectrum.
This prompted Mr Zelaya to declare the agreement "dead".
The deal, which asked Congress to vote on whether to reinstate Mr Zelaya, appears to have been too vague about the mechanisms for deciding who should lead the unity government.
The two sides interpreted it differently.
Congress had not voted by the time the deadline for forming the government passed, and was still waiting for an opinion from the Supreme Court on whether Mr Zelaya should be reinstated.
In the run up to the power-sharing deal, the interim government consistently said Mr Zelaya's return to power was impossible, while Mr Zelaya always said his return as president was "non-negotiable".