Islam, the predominant religion throughout Central Asia, was brought to the region by the Arabs in the 7th century. Since that time, Islam has become an integral part of Tajik culture. Tajikistan is a secular country, but the post-Soviet era has seen a marked increase in religious practice in the country. The majority of Tajikistan's Muslims adhere to the Sunni branch of Islam, and a smaller group belongs to the Shia branch of Islam. The Russian Orthodox faith is the most widely practiced of other religions, although the Russian community shrank significantly in the early 1990s. Some other small Christian groups now enjoy relative freedom of worship. Tajikistan also has a small Jewish community. Islam Sunni Islam is, by far, the most widely practiced religion in Tajikistan. According to a 2009 U.S. State Department release, the population of Tajikistan is 98% Muslim (approximately 95% Sunni and 3% Shia). The Sunni branch of Islam has a 1,200-year-old tradition among the sedentary population of Central Asia, including the Tajiks with some Sufi orders. A small minority group, the Pamiris, are members of a much smaller denomination of Shia Islam, Ismailism, which first won adherents in Central Asia in the early 10th century. Despite persecution, Ismailism has survived in the remote Pamir Mountains. During the Soviet Era During the course of seven decades of political control, Soviet policy makers were unable to eradicate the Islamic tradition, despite repeated attempts to do so. The harshest of the Soviet anti-Islamic campaigns occurred from the late 1920s to the late 1930s as part of a Union-wide drive against religion in general. In this period, many Muslim functionaries were killed, and religious instruction and observance were curtailed sharply. After the German invasion of the Soviet Union in 1941, official policy toward Islam moderated. One of the ensuing changes was the establishment in 1943 of an officially sanctioned Islamic hierarchy for Central Asia, the Spiritual Administration of the Muslims of Central Asia and Kazakhstan. Together with three similar organizations for other regions of the Soviet Union having large Muslim populations, this administration was controlled by the Kremlin, which required loyalty from religious officials. Although its administrative personnel and structure were inadequate to serve the needs of the Muslim inhabitants of the region, the administration made possible the legal existence of some Islamic institutions, as well as the activities of religious functionaries, a small number of mosques, and religious