Army Day is observed in Jordan every June 10, commemorating the anniversary of the Great Arab Revolt against the Ottoman Empire, which began in 1916. This day marks the uprising initiated by Sharif Hussein bin Ali, who led his supporters in an attack on the Ottoman garrison in Mecca. The revolt lasted for two years and contributed to the eventual establishment of the Emirate of Transjordan. Although the Royal Jordanian Army was officially formed in 1920, its roots trace back to the Hashemite forces involved in the revolt, which is why this date is significant. Celebrations typically include a military parade attended by the King of Jordan, although Army Day is not a public holiday and remains a regular working day. The Royal Jordanian Army, part of the Jordanian Armed Forces, has an estimated size of 90,000 active personnel and 60,000 reserve personnel.