The army was divided into four groups led by Sharif Husayn's sons, ‘Ali, ‘Abdullah, Faysal, and Zayd. Nuri al-Said and his brother-in-law Ja'far al-Askari, who had previously been a Colonel in the Ottoman Army, joined the Sharifian Army because of their strong belief in Arab nationalism and rose to become leaders within the Sharifian Army. The first few months of the revolt were led by ‘Ali and his forces which consisted of about 30,000 men, most of whom were irregular forces who only fought for a short period of time. By September 1916 these 30,000 were divided amongst all four of Husayn's sons who each now had at least 6,000 irregular forces under their control. The Sharifian Army consisted of about 4,000 regular forces by the beginning of 1917. The majority of these regular soldiers served under Husayn or ‘Ali. As the revolt continued, Faysal emerged as the most successful of the four brothers and most of the forces fell under his control. The fact that Faysal worked alongside Lawrence of Arabia gave him access to more British intelligence, which is a large part of the reason he was the most successful.