President: Abdrabbuh Mansour Hadi (resigned)
Abdrabbuh Mansour Hadi took office after an uncontested presidential election in February 2012, marking the final stage in the exit of Ali Abdallah Saleh, Yemen's longest-serving leader in recent times.
Mr Saleh signed an agreement in November 2011 in which he undertook to hand power to Mr Hadi, his deputy, ahead of the early presidential election. The deal, signed in Saudi Arabia, was aimed at taking Yemen back from the brink of civil war.
Mr Hadi agreed to grant Mr Saleh immunity from prosecution and to head an interim national unity government until the February poll.
A southerner, born in Abyan province in 1945, Mr Hadi rose through the ranks of the army of South Yemen and that of unified Yemen after 1990. He become defence minister and then vice-president in 1994, leading the military campaign against southern secessionists in the brief civil war.
With President Saleh sidelined by the 2011 popular uprising against his 33-year authoritarian rule, the low-key Mr Hadi emerged as a figure trusted enough by the pro-Saleh military and tribal factions, pro-democracy protesters, southerners and Yemen's powerful Saudi neighbour to manage the transition to free elections.
These were originally due to be held in 2014, but have been postponed while the National Dialogue Conference - a multi-party body set up to oversee the country's political transition - seeks to secure agreement on a new constitution, the latest version of which proposes dividing Yemen into a six-region federation.
Mr Hadi has faced a monumental task in trying to hold Yemen's opposing factions together against a background of economic stagnation, al-Qaeda violence and deepening poverty.
The Houthi Shia insurrection in the north and the increasing strength of Al-Qaeda in the Arabian Peninsula (AQAP) - the Yemeni branch of the jihadist network - have come to represent the biggest challenges to Mr Hadi's efforts to maintain stability.