Islam, the second largest religion in the world, has as many as 138.2 million followers in India or 13.4 per cent of the population (2001 census). This makes India the country with the second largest Muslim population after Indonesia. Muslims believe in one god, Allah, and base their laws on their holy book, the Qur’an, and the Sunnah, the practical principles of their religious leader Prophet Muhammad. The most important Muslim practices are the five basic Pillars of Islam: the declaration of faith, praying five times a day, giving money to charity, fasting and a once-in-a-lifetime pilgrimage to Mecca.
Muslims believe that Islam has always existed, but that the final revelation of their religion was made through Prophet Muhammad in the 7th century in the holy city of Mecca. In subsequent centuries, Islam spread across the Middle East and Asia through Muslim communities, traders or through conquest. According to historical records, it was brought to India in the 7th century by Arab merchants who propagated the religion wherever they went. In subsequent years, the spread of Islam was consolidated through Muslim invaders.
Full-scale Muslim conquests of India began in the 10th to 11th centuries headed by Mahmud of Ghazni, which further consolidated the spread of Islam in the country. The Khilji, Tughlaq, Sayyid and Lodhi dynasties of the Delhi Sultanate, as well as the Mughal Empire in the 16th to 18th centuries contributed to the fusion of Hindu and Islamic thought, art and architecture and the development of the Persian and Urdu languages.
The centuries of Islamic rulers saw the rapid spread of Islam through India, both through peaceful means and forcible conversions. Islamic mystics known as Sufis played a key role in the spread of Islam in India. They succeeded in propagating the tenets of Islam in an unorthodox way which appealed to Hindus. Moreover, under the Mughals, Hindus were subjected to harsh taxation—the hated Islamic poll tax or jizya and another pilgrimage tax, which forced many Hindus to convert to Islam. Mughal Emperor Akbar, the most benevolent of the Mughal rulers, abolished the pilgrimage tax in 1563 and the jizya poll tax the following year, but the jizya was reinstated by Mughal Emperor Aurangzeb in 1679. The Masjid-i-Jahan Numan, better known as the Jama Masjid, is the largest and most prominent mosque in India. It was built by Mughal Emperor Shah Jahan and is located in the old part of Delhi.
Today, the Muslims of India, like the rest of the Muslim world, are divided into two main sects, Sunni and Shia. There are also many different sub-sects. In west India are to be found the Bohra and Khoja communities; in the state of Kerala in south India exists the Mophilla community; while in the north are the Pathans.