Dec 24 (Reuters) - Somali President Abdullahi Yusuf has decided to resign, his spokesman said. The announcement followed the resignation of a politician Yusuf named prime minister last week, who said he did not want to be an obstacle to peace.

Here is a timeline of events since Islamists first seized the capital, Mogadishu:

June 2006 - The Somalia Islamic Courts Council (SICC) seizes Mogadishu from U.S.-backed warlords and takes control of parts of southern Somalia.

Dec. 28 - Islamists flee Mogadishu ahead of a joint Ethiopian and Somali government force which captures the city.

Jan. 8, 2007 - Abdullahi Yusuf arrives in Mogadishu for the first time since he became president in 2004.

Aug. 30 - Yusuf winds up a six-week-long peace conference, which has no visible impact on growing insurgency. Islamists and some other opposition figures boycott the talks.

March 26, 2008 - Islamist fighters seize Jowhar, the most significant of several towns recently captured.

May 1 - U.S. air strike kills al Shabaab leader Aden Hashi Ayro.

Aug. 18 - Somalia formally signs a peace deal with some opposition figures, but the pact is rejected by hardliners.

Aug. 22 - Al Shabaab insurgents seize Kismayu, a strategic southern port, after fighting that killed 70 people.

Aug. 25 - U.N.'s Food Security Analysis Unit says more than 3.2 million people need humanitarian aid.

Oct. 3 - Islamists, now controlling swathes of southern Somalia, warn Western charities working there not to meddle in their affairs.

Nov. 12 - Rebels take port of Merka, 90 km (56 miles) southwest of Mogadishu, after government-aligned militia leave.

Nov. 14 - Al Shabaab fighters move into Elasha town near Sinkadheer, where Ethiopian troops are based. Sinkadheer is 15 km (9 miles) south-west of Mogadishu.

-- President Yusuf admits Islamist insurgents control most of the country and raised the prospect his government could completely collapse.

Nov. 15 - The Sirius Star, a Saudi supertanker, is hijacked by pirates 450 miles southeast of Mombasa. The tanker is carrying $100 million of oil.

Nov. 28 - Ethiopia says it will withdraw its troops from Somalia by the end of this year, piling pressure on Somalia's feuding government.

Dec. 10 - Somalia's moderate Islamist leader Sheikh Sharif Ahmed returns to Mogadishu for the first time in two years. A local rights group says 16,210 civilians have been killed in fighting since then.

Dec. 11 - Ethiopian Prime Minister Zenawi says that AU peacekeepers have asked Ethiopian troops planning to leave the country to help them quit Mogadishu too.

Dec. 14 - President Yusuf sacks Prime Minister Nur Hassan Hussein, saying the government has failed to extend security to the nation. The next day parliament votes to reinstate him.

Dec. 16 - Yusuf names former interior minister Mohamed Mohamud Guled as prime minister, snubbing parliament.

Dec. 24 - Yusuf announces he will resign on Dec. 27, hours after newly appointed Guled resigns.

AlertNet news is provided by