Abd-Rabbu Mansour Hadi, who resigned in January as Yemen's president amid pressure from Shia Houthi rebels, assumed office in 2012 after spending 17 years as vice-president.
Hadi was elected president after protests lasting nearly a year against former president Ali Abdullah Saleh, but he set about governing a country beset by a host of problems, including a Shia rebel movement and a growing threat from al-Qaeda.
A sole candidate in the referendum-like elections held in 2012, the Sunni politician's ascendency to power saw Yemen become the first Arab Spring nation where an uprising led to a negotiated settlement.
The vote was a condition of the power-transition deal signed by Saleh in 2011 after mass protests calling for him to step aside.
Under the deal, brokered by the Gulf Co-operation Council made up of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates, Saleh transfered constitutional powers to Hadi, who he had appointed as vice-president in 1994.
The 68-year-old former soldier from Yemen's south was considered by most as the consensus candidate.
But two major opposition groups - the separatist Southern Movement and the Houthi rebels - boycotted the poll.
The uprising's main proponents had asked Yemenis to support Hadi and posters of the vice-president were plastered on buildings and streets in the capital Sanaa.
Hadi had local, regional and international support and was a respected leader with a vision for the future.
When news of the presidential poll came, crowds in Sanaa chanted "Hadi, take the key, the slaughterer's rule has ended”, a reference to Saleh's leadership.
Yemen's Nobel Peace laureate Tawakkul Karman had urged Yemenis to vote for Hadi, saying his election would mark "the fruit of the popular youth uprising".
Hadi was expected to launch a national dialogue, the first step in the transitional period that sought to end in legislative and presidential elections within two years.
But many Yemenis had expressed concern over the role of the country's security forces, a major challenge Hadi had to deal with.
Security forces remained under the control of Saleh's sons and nephews, and were responsible for much of the bloodshed that occurred during the crackdown on protests.
Hadi was sworn in as Saleh returned home from the US where he received treatment for injuries sustained in an attack on his palace.
Many feared his return would stock tensions but US President Barack Obama had voiced support for Hadi's new leadership.
Obama said in a letter that he looked forward to deeper relations between the two nations and promised that the US would be "a strong and reliable partner". He wrote that Yemen would become a symbol of political transformation "when people resist violence and unite under a common cause".
Saleh's critics had repeatedly accused the veteran leader of intentionally allowing al-Qaeda to expand its influence in the country's lawless south and east to demonstrate that only he can fight the spread of terror.