ethnicity, a dynamic Muslim community, Muhammadiyah developed rapidly. In 1938, the organisation claimed 250,000 members, managed its 834 mosques, 31 libraries, 1,774 schools, and 7,630 ulema. The Minangkabau Merchants spread organization to the entire of Indonesia. During the 1965-66 political turbulence and violence, Muhammadiyah declared that the extermination of the Indonesian Communist Party constituted Holy War, a view endorsed by other Islamic groups. (See also: Indonesian killings of 1965-66). During the events surrounding the 1998 fall of President Suharto, some parts of Muhammadiyah urged the leadership to form a party. Therefore, the leadership, including Muhammadiyah's chairman, Amien Rais, founded the National Mandate Party. Although gaining large support from Muhammadiyah members, this party has no official relationship with Muhammadiyah. The leader of Muhammadiyah said the members of his organisation are free to align themselves with political parties of their choosing, provided such parties have shared values with Muhammadiyah. In 2008, with 29 million members, Muhammadiyah was the second largest Muslim organization in Indonesia, after Nahdlatul Ulama. Doctrine The central doctrine of Muhammadiyah is Sunni Islam. However, it emphasizes the authority of the Qur'an and the Hadiths as supreme Islamic law that serves as the legitimate basis of the interpretation of religious belief and practices. This is contrasted with traditional practices where shariah law is invested in religious schools by ulema. The main focus of the Muhammadiyah movement is to heighten people's sense of moral responsibility, purifying their faith to true Islam. Theologically, Muhammadiyyah adheres to doctrines of Salafiyya; calling for directly returning to the Qur'an and Sunnah and the understanding of the Imams of the Salaf (early generations), including the eponyms of the four Sunni Madh'habs (legal schools). It advocates for a purification of faith from various local customs which they consider to be superstitious, heretical and forms of shirk (polytheism). Muhammadiyya directly traces its scholarly heritage to the teachings of Muhammad Rashid Rida (d. 1935 C.E / 1354 A.H), Muhammad ibn 'Abd al-Wahhab (d. 1792 / 1206 A.H), and the medieval theologians Ahmad Ibn Taymiyyah (d. 1328 C.E / 728 A.H) and Ibn Qayyim (d. 1350 / 751 A.H). Muhammadiyah strongly opposes syncretism, where Islam had coalesced with animism (spirit worship) and with Hindu-Buddhist elements that were spread among communities from the pre-Islamic period. Muhammadiyah opposes the tradition of Sufism that allows a Sufi leader (shaykh) to be the formal authority over Muslims. As of 2006, the organization was said