Slavery existed in the area of later Saudi Arabia from antiquity onward. Hejaz (the western area of modern day Saudi Arabia), which encompasses approximately 12% of the total land area of Saudi Arabia, was under the Ottoman Empire 1517–1918, and as such nominally obeyed the Ottoman laws. When the area became an independent nation first as the Kingdom of Hejaz and then as Saudi Arabia, it became internationally known as a slave trade center during the Interwar period. After World War II, growing international pressure eventually resulted in the formal abolition of the practice. Slavery was formally abolished in 1962.