President Ali Abdullah Saleh returned to Yemen on Friday after three months in Saudi Arabia recovering from an assassination attempt.
Below is a timeline of events since protests against Saleh's 33-year rule began this year:
Jan 29, 2011 - Yemen's ruling party calls for dialogue with the opposition in a bid to stem anti-government protests.
-- Saleh supporters attack and disperse Yemenis who try to march to the Egyptian embassy in Sanaa to express solidarity with Egyptian anti-government demonstrators. Yemeni protesters chant "the people want the regime to fall."
Feb 3 - A day of anti-government protests brings more than 20,000 people onto the streets in Sanaa.
March 2 - The opposition presents Saleh with a plan for a transition of power, offering him a graceful exit.
-- Saleh says he will draw up a new constitution to create a parliamentary system. The opposition rejects the proposal.
March 18 - Snipers kill 52 protesters at Sanaa University after Friday prayers. Saleh declares a state of emergency.
March 20 - Saleh dismisses his government.
March 21 - Senior army commanders, including Saleh ally General Ali Mohsen, commander of the northwest military zone, say they have switched support to pro-democracy activists.
March 23 - Saleh offers to step down by the end of 2011. He also proposes to hold a referendum on a new constitution, then a parliamentary election and presidential vote.
March 25 - Saleh says he is ready to cede power to stop more bloodshed. Thousands rally in "Day of Departure" protests.
March 29 - Saleh holds talks with Mohammed al-Yadoumi, head of the Islamist Islah party, once a partner in his government. Saleh proposes staying in office until elections are held but transferring his powers to a caretaker.
-- The opposition rejects the offer.
April 2 - The opposition proposes a five-point plan for the army and security forces to be restructured by a vice-president acting as temporary president.
April 6 - Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani says the regional bloc Gulf Cooperation Council (GCC) will strike a deal for Saleh to leave.
April 18 - Ruling party members form Justice and Development Bloc to support protests.
April 23 - Saleh agrees to step down in weeks in return for immunity from prosecution. The opposition agrees to the plan.
April 25 - The opposition agrees to join a transitional government under a Gulf-negotiated plan for Saleh to step aside.
April 30 - Saleh appears to sabotage the plan by refusing to sign in his capacity as president. GCC mediators tell Yemen's opposition Saleh will only sign the deal as leader of his party.
May 13 - Huge crowds across Yemen demand Saleh leave. Saleh declares: "We will confront a challenge with a challenge."
May 14 - GCC Secretary-General Abdullatif al-Zayani arrives in Sanaa to revive the stalled deal.
May 21 - Yemen's opposition signs the transition deal.
May 22 - Five members of the ruling party sign the deal, but Gulf Arab states suspend it after Saleh asks for additional conditions and diplomats fail to persuade him to sign it.
-- Loyalist gunmen trap Western and Arab diplomats in the UAE embassy in Sanaa, blocking mediators from going to the presidential palace. Diplomats later leave by helicopter.
May 23 - Saleh apologizes to the UAE but foreign governments pile criticism on him over his refusal to sign.
May 24 - Saleh's refusal to sign the power transfer deal sparks street battles in Sanaa between security forces and a powerful tribal group, the Hashed tribal alliance, led by Sadeq al-Ahmar. At least 20 people are killed.
May 26 - Several countries, including United States, ask their diplomats to leave.
May 28 - Security forces and tribesmen agree to a truce.
May 30 - Truce breaks down, with militants regaining control of ruling party building in the Hasaba district of Sanaa.
June 3 - Opposition parades through Sanaa the bodies of 50 people it says were killed in clashes with Saleh's forces.
-- Death toll climbs to more than 370.
-- A bomb explodes at Saleh's palace in Sanaa, wounding the president, the prime minister, and the parliament speaker.
-- Saleh leaves for treatment in Riyadh hospital.
June 4 - Vice-President Abd-Rabbu Mansour Hadi takes over as acting president and supreme commander of the armed forces.
June 5 - Saleh undergoes surgery to remove shrapnel from his chest. Crowds cheer what they hope is his exit from power.
June 6 - Opposition calls for official transfer of power to VP, U.S. pushes for immediate democratic transition.
June 13 - Suspects arrested over attack on Saleh.
June 24 - U.N. Security Council voices its "grave concern" about Yemen's deteriorating situation, urges restraint.
July 5 - Yemeni warplanes bomb militant-held cities in southern Abyan province. More than 50,000 civilians flee after month of clashes between army and militants linked to al Qaeda.
July 7 - Saleh makes first televised appearance since attack, says he supports dialogue and welcomes power sharing.
July 10 - U.S. counter-terrorism official John Brennan meets Saleh in Riyadh, urges him to sign a transition plan.
July 25 - Opposition rejects government plan for dialogue, refusing to negotiate until Saleh signs transition deal.
Aug 15 - Government blames opposition tribal leader Hamid al-Ahmar for attack which wounded Saleh.
Aug 20 - Several opposition figures quit newly formed National Council, exposing division in anti-government movement.
Aug 29 - Saleh says he is committed to holding elections for a new president as soon as possible.
Sept 7 - Ruling party approves changes to power transfer plan, which would transfer Saleh's powers to his vice president but give him three months to formally step down.
Sept 12 - Saleh empowers vice president to sign deal. The opposition is skeptical of Saleh's call for further talks before the VP signs the deal.
Sept 18 - Protests escalate as security forces fire on demonstrators, killing 21 and wounding dozens.
Sept 19 - Security forces kill at least 20 people, some shot by snipers, in a crowd of protesters demanding Saleh's removal.
Sept 20 - Battles between pro- and anti- Saleh forces kill 12 people.
Sept 21 - Yemeni forces clash again with soldiers loyal to defected top general Ali Mohsen, violating a short-lived truce.
-- GCC Secretary General Abdbullatif al-Zayani left Sanaa after failing to get a power transfer deal signed.
Sept 22 - Fighting between pro- and anti-government forces spreads through Sanaa bringing the death count from five days of violence to more than 100.
Sept 23 - President Ali Abdullah Saleh returns to Yemen from Saudi Arabia, greeted by the sound of gunfire and explosions.
(Compiled by David Cutler and Nour Merza)