The Rer Aw Hassan (Somali: Reer Aw Xassan) (English: People of Hassan) is a clan based in Koonfur Galbheed, region of Somalia and along the border between Ethiopia and Somalia. They live in towns such as Buurukur, Ferfer and Abaaley in Somali Region of Ethiopia.Reer-Aw-Xassan members are also found in parts of Kenya like Mandera, and in Southern Somalian towns including Mogadishu, Merca, Qoryoley, and Kismayo Khalalio, Mandera, Kenya. In origin the Rer Aw Hassan are Asharaf, they are descendants of Hussein, the son of Fatima, daughter of the Prophet. A Sheikh, known as Hassan or Kaweyne, came from Yemen to Somalia in the 15th century, where he married two women.There are four major subclans of the Reer Aw Xasan: Saa'id and Nuur, Abdalla, Abdirahman. Saa'id, which has the largest number of people, are further divided into three sub-groups: the Reer aw Kheyre, ree aw Ali and the Reer aw-Xuuriye.The Nur sub clan is divided into four sub-groups:The Reer Aw-mahdi,Reer Aw Elmi,Reer aw Udgoone and Reer aw ahmed.