The modern Republic of Yemen was born in 1990 when traditionalist North Yemen and Marxist South Yemen merged after years of border wars and skirmishes. But the peace broke down in 1994 and a short civil war ended in defeat for separatist southerners and the survival of the unified Yemen.
Since unification Yemen has been modernising and opening up to the world, but it still maintains much of its tribal character and old ways. Tensions persist between the north and the south; some southerners say the northern part of the state is economically privileged.
Since the summer of 2009, hundreds have been killed and more than a quarter of a million people displaced by clashes between government troops and northern Houthi rebels belonging to the minority Shia Zaidi sect. The government declared a ceasefire with the northern rebels in February 2010.
Many people wear traditional dress and the custom of chewing the narcotic plant khat in the afternoons is still widely observed. Yemen has attracted the curiosity of a growing number of tourists, although foreigners have been kidnapped by groups seeking to force concessions from the authorities.
Yemen has also gained a reputation as a haven for Islamic militants. Towards the end of 2009, the country came under the spotlight after crackdowns on al-Qaeda-linked militancy in Afghanistan and Pakistan raised fears that it was becoming a key training centre for militants.
After a Yemen-based branch of al-Qaeda claimed that it was behind a failed attack on a US airliner on Christmas Day 2009, the government stepped up its efforts to clamp down on Islamic militants, but warned that it would need help to win the battle against militancy.
The truce with northern rebels in February 2010 allowed the government to focus its attention on the struggle against al-Qaeda and southern separatists.