Religion in South Asia

In 2010, South Asia had the world's largest population of Hindus, about 510 million Muslims, over 27 million Sikhs, 35 million Christians and over 25 million Buddhists. Hindus make up about 68 percent or about 900 million and Muslims at 31 percent or 510 million of the overall South Asia population, while Buddhists, Jains, Zoroastrians, Sikhs, and Christians constitute most of the rest. The Hindus, Buddhists, Jains, Sikhs, Zoroastrians, and Christians are concentrated in India, Nepal, Sri Lanka and Bhutan, while the Muslims are concentrated in Afghanistan (99%), Bangladesh (91%), Pakistan (96%) and Maldives (100%).

Indian religions (also known as Dharmic religions) are the religions that originated in the Indian subcontinent; namely Hinduism, Jainism, Buddhism, Sikhism, and Zoroastrianism. The Indian religions are distinct yet share terminology, concepts, goals and ideas, and from South Asia spread into East Asia and Southeast Asia. Early Christianity and Islam were introduced into coastal regions of South Asia by merchants who settled among the local populations. Later Sindh, Balochistan, and parts of the Punjab region saw conquest by the Arab caliphates along with an influx of Muslims from Persia and Central Asia, which resulted in spread of both Shia and Sunni Islam in parts of northwestern region of South Asia. Subsequently, under the influence of Muslim rulers of the Islamic sultanates and the Mughal Empire, Islam spread in South Asia. About one-third of the world's Muslims are from South Asia.

Ancient period
South Asia was primarily Hindu in ancient times. Buddhism appeared around 500 BCE.

Christianity and Islam made an appearance in Kerala during this time period; Saint Thomas is believed to have travelled to Kerala soon after the death of Jesus and converted some people, while the first mosque to be built in India was built during the Islamic prophet Muhammad's lifetime in Kerala. Islam also established itself in Sindh due to Umayyad invasions soon after Muhammad's death.

Some Jews and Zoroastrians came to South Asia because they were fleeing religious persecution.

Medieval period
Centuries of Islamic invasion and rule over South Asia in the medieval era began to change the religious character of the region. Sufism played a significant role in the spread of Islam during this time. Sikhism emerged in this era, bringing a message of equality and creating military resistance to Muslim rule.

Nepal's formation during this period occurred in part due to the desire of Hindus to avoid being influenced by the dominant Muslim Mughal Empire and British Christian missionaries.

Colonial era
Christianity grew to some extent during the colonial era; the Goa Inquisition committed by the Portuguese helped Catholicism establish itself in Goa, while British missionaries spread Christianity through the rest of India.

Modern era
Religious tensions increased with the independence of British India, as it was partitioned into a Hindu-majority India and a Muslim-majority Pakistan (which later became Pakistan and Bangladesh), and many died during the creation of the new countries. Tensions further increased with Pakistani terrorist attacks on and Pakistani military conflicts with India.

Religious nationalism has grown in the post-colonial era. Pakistan converted from a secular republic to an Islamic Republic after Independence, while Bangladesh made Islam the state religion (though while maintaining secularism in the Constitution). Hindu nationalism has grown since the 2014 election of the Bharatiya Janata Party (BJP) in India.