Hanbali is one of the four schools (Maddhabs) of Fiqh or religious law within Sunni Islam. It is considered to be the most conservative of the four schools. The school was started by the students of Imam Ahmad, whose name was Ahmad bin Hanbal (d. 855). Hanbali jurisprudence is predominant among Muslims in the Arabian Peninsula, although students of Islam throughout the world study and may choose to observe its conclusions about Islamic practise. The Hanbali school is followed by less than 5% of the world's Muslim population. It is presently the school of jurisprudence used in modern day Saudi Arabia.