Yemen (officially known as the Republic of Yemen), is an Arab country in Southwest Asia, occupying the southwestern to southern end of the Arabian Peninsula. Yemen is the second largest country in the peninsula, occupying 527,970 km2. The coastline stretches for about 2,000 km. It is bordered by Saudi Arabia to the north, the Red Sea to the west, the Gulf of Aden and Arabian Sea to the south, and Oman to the east. Although Yemen's constitutionally stated capital is the city of Sana'a, the city has been under rebel control since February 2015. Because of this, Yemen's capital has been temporarily relocated to the port city of Aden, on the southern coast. Yemen's territory includes more than 200 islands, the largest of these is Socotra.
Yemen was home of the Sabaeans (biblical Sheba), a trading state that flourished for over a thousand years and probably also included parts of modern-day Ethiopia and Eritrea. In 275 AD, the region came under the rule of the later Jewish influenced Himyarite Kingdom. Christianity arrived in the 4th century AD whereas Judaism and local paganism were already established. Islam spread quickly in the 7th century and Yemenite troops were crucial in the expansion of the early Islamic conquests. Administration of Yemen has long been notoriously difficult. Several dynasties emerged from the 9th to 16th century, the Rasulid being the strongest and most prosperous. The country was divided between the Ottoman and British empires in the early 20th century. The Zaydi Mutawakkilite Kingdom of Yemen was established after World War I in North Yemen before the creation of Yemen Arab Republic in 1962. South Yemen remained a British protectorate until 1967. The two Yemeni states united to form the modern republic of Yemen in 1990.