How it unfolded

September 21, 2014: Al Houthi militants seize government headquarters, state radio and military sites in Sana’a.

February 21, 2014: President Abd Rabbo Mansour Hadi escapes house arrest and flees south to second city Aden. Al Houthis advance on the south.

March 26, 2015: Saudi Arabia begins Operation Decisive Storm with air strikes on Al Houthis after forging a coalition of nine countries to defend Hadi.

May 5: Al Houthis bombard the Saudi border town of Najran, killing several people.

June 17: More than 30 people killed in bombings claimed by Daesh at a Shiite mosque in Sana’a. The attacks come almost three months after Daesh killed 142 people in bombings at Shiite mosques in the capital.

July 17: Yemen’s exiled Prime Minister Khaled Bahah announces the liberation of Aden.

August 15: Yemen resistance forces retake a fifth southern province, extending their gains against Al Houthis.

September 4: An arms depot blast kills 52 soldiers from the United Arab Emirates, 10 Saudi troops and five from Bahrain. Thousands of heavily equipped Arab soldiers are sent to Yemen.

September 13: Yemeni resistance forces backed by the coalition, begin a major ground offensive in Marib.

November 17: President Hadi returns from exile in Saudi Arabia to Aden.

December 6: A car bombing claimed by Daesh kills Aden’s recently appointed governor.

December 8: The government says the country’s warring sides are preparing to observe a week-long truce to coincide with UN-mediated peace talks to start on December 15 in Switzerland.