Islamic hospitals were different from other hospitals because Muslims were led to form bimaristans by Muhammad, who taught that God would not create a disease without creating a cure. Mobile hospitals were the first version of the bimaristans. According to tradition, the first mobile hospital was located in a tent to treat war victims from the Battle of the Ditch (627 CE). Mobile Hospitals consisted of medications, food and water, doctors, and pharmacists to aid the patients. The use of the mobile bimaristan was not limited to the Battle of the Ditch. From that point on, Caliphs and rulers continuously developed mobile hospitals through the use of pharmacists, newly-created medical equipments and instruments, and the employment of qualified physicians. One of the advantages to having mobile bimaristans was that it allowed the state to reach those in need who may not have previously been able to receive treatment due to their remote location. These services from the mobile hospital transitioned into the other Islamic hospitals that were built as well. Bimaristans were generally located in urban areas. Though the Islamic realm was very large, Baghdad, Damascus, and Cairo housed the most well-known Islamic hospitals. The first six bimaristans show major changes within Islamic hospitals in a short period of time. The first bimaristan, built in 706 in Damascus by the Umayyad Caliph named Al-Walid, focused on treating individuals with leprosy. Around the same period the second bimaristan was built in Cairo. The third and fourth Islamic hospitals were built in Baghdad. The third bimaristan was built in 805 by Caliph Harun al-Rashid. This Islamic hospital in Baghdad was the first documented general hospital.