Mas Mansoer was born on 25 June 1896 in Kampung Sawahan, north of Surabaya. His father was Kyai Hajji Mas Ahmad Marzuki, a descendant of the Sumenep royal family and a friend of Kyai Hajji Ahmad Dahlan. His mother was a woman from Surabaya who was of mixed Buginese and Minang descent. At the age of 12, Mansoer went to Mecca to study Islam. He then enrolled at Al-Azhar University in Egypt. During his studies, he read several Western literary works about freedom, humanism, and democracy. He also observed how Egyptian people fought against British colonists to obtain their independence, which influenced his later views. After graduating from Al-Azhar, Mansoer returned to Surabaya and became an ustaz at the Mufidah pesantren. During this period, he felt that the colonial government hindered the teaching of Islam. This situation made him join Muhammadiyah and Persatuan Bangsa Indonesia. He preached in remote areas. In 1914, Mansoer and Abdul Wahab Hasbullah founded an educational organization named Nahdhatul Wathan. They also joined the Indonesche Study Club, an organization led by Dr. Sutomo. Later, he became a chairman of East Java branch of Muhammadiyah. In 1937, he became a chairman of Muhammadiyah through an election at the 26th Muhammadiyah Congress. Because of his widespread influence, the colonial government offered him a position in the Het Kantoor van Inlandsche Zaken as the head of institution of religious affairs. However, he refused it. Mansoer took the initiative in formatting the Majelis Islam A'la Indonesia on 25 September 1937. The purpose of the organization was to aid clerics throughout Indonesia in networking and building relationships with each other, both physically and spiritually. Under influence from the nationalism movement, MIAI was also involved in opposing the colonial government, such as in the like Gabungan Politik Indonesia led by M. H. Thamrin. In 1938 he founded the Partai Islam Indonesia with Dr. Sukiman. During the Japanese occupation, Mansoer was under pressure due to his activities with Muhammadiyah. Mansoer, Kyai Hajji Wahid Hasyim, and Kyai Hajji Taufiqurrahman then formed an Islamic organization called Masyumi. After the group was formed, the Japanese government banned all political organizations and formed PUTERA to spread its propaganda. Mansoer, along with Soekarno, Mohammad Hatta, and Soewardi Soerjaningrat, were appointed as leaders in 1942; collectively they were known as the Empat Serangkai. He accepted the appointment and resigned as Chairman of Muhammadiyah. Mansoer resigned from PUTERA in 1944 by reason of illness. During this period, Mansoer conveyed an idea of a roemah jang moerah dan sehat in a meeting with other intellectuals and Japanese officers; this was hoped to solve housing problems faced by native Indonesians. His idea was supported by Soekarno. He also drew a blueprint for the project. Before the Proclamation of Indonesian Independence, Mansoer became a member of the Panitia Persiapan Kemerdekaan Indonesia. During the national revolution, Mansoer helped the people of Surabaya in defendingthe city against the British Army. Then, he was arrested by the Dutch, and was told to give a speech and convince the people of Surabaya to surrender; however, he refused. As a result, Mansoer was jailed in Kalisosok Prison in Surabaya. Mansoer died on 25 April 1946 in the prison. His remains were buried in Gipu, Surabaya.
Religious views
With respect to banking, Mansoer issued a fatwa that all kinds of bank interest are haraam. However, doing business in banking was still allowed. On another issue, during the Nineteenth Congress of Muhammadiyah, Hajji Rasul contended that unisex majlis were haraam, but Mansoer disagreed. After discussing it, they agreed to declare them makruh. In the purification of Islamic teachings, Mansoer prohibited bid‘ah, taqlid, and takhayul in worship. He also forbade the tradition of grave pilgrimages, selametan, and doing a talqin for a body. He said that setbacks suffered by Muslims were caused by their weak beliefs and egoism, and that to fix these problems, Muslims should base their lives on the Quran and Hadiths. In his work Risalah Tawhid dan Sjirik he stated that another cause of Muslims' weakness was interference in Islamic thought and practices from polytheism.
