Saud of Saudi Arabia
In 1915, when Mahmud Hasan went into self-exile in Hijaz, Saudi Arabia, Usmani filled his position as the teacher of "Sahih Muslim", a book of teachings of prophet Muhammad. In 1925, Sultan Abdul Aziz Ibn Saud of Saudi Arabia scheduled a conference for prominent religious scholars from all over the world. A deputation of a number of 'ulama' from India participated in this conference, it is believed that they chose Usmani as their leader after having a short conversation with him.