At the start of the 20th century the
Ottoman Empire controlled what is now Jordan and Iraq, with the interior further south consisting of loosely organised Arab groupings, occasionally forming emirates, most prominent of which was the
Emirate of Nejd and Hasa ruled by the
al-Saud family. During the
First World War an
Arab Revolt, supported by Britain, succeeded in removing the Ottomans from most of the Middle East. As a result of the secret 1916 Anglo-French
Sykes-Picot Agreement Britain gained control of the Ottoman Vilayets of
Mosul,
Baghdad and
Basra, which it organised into the
mandate of Iraq in 1920, and also the southern half of the
Vilayet of Syria (roughly, modern western Jordan). This latter area was contested between Britain, the newly formed
Arab Kingdom of Syria, Zionists in the
Mandatory Palestine, and Ibn Saud's new kingdom
Saudi Arabia, resulting in a confused period in which the region was essentially an
ungoverned space. Eventually in 1921 Britain declared a mandate over the region, creating the
Emirate of Transjordan, under the semi-autonomous rule of
King Abdullah I. No precise boundary between the Iraq and Transjordan mandates was drawn at that time. ==Border crossings==