Contrary to popular belief, Islam came to South Asia prior to Muslim invasions of India. Islamic influence first came to be felt in the early 7th century with the advent of Arab traders. Trade relations between Arabia and the subcontinent are very ancient. Arab traders used to visit the Malabar region, which was a link between them and ports of South East Asia, to trade even before Islam had been established in Arabia. According to Historians Elliot and Dowson in their book ‘The History of India as told by its own Historians,’ the first ship bearing Muslim travelers was seen on the Indian coast as early as 630 AD. It was with the advent of Islam that the Arabs became a prominent cultural force in the world. The Arab merchants and traders became the carriers of the new religion and they propagated it wherever they went.
The first Indian mosque was built by Malik ibn Deenar in 629 A.D, at the behest of the local King Cheraman Perumal, who is considered the first Indian Muslim. He lived during the life time of the Messenger of Allah (peace and blessings be upon him) in Kodungallur, in district of Thrissur, Kerala and is said to have traveled to Arabia to meet the Messenger of Allah and perform the Last Hajj with him.
In the 8th century, the province of Sindh (in present day Pakistan) was conquered by an Arab army led by Muhammad bin Qasim. Sindh became the easternmost province of the Umayyad Caliphate.
In the first half of the 10th century, Mahmud of Ghazni added the Punjab to the Ghaznavid Empire and conducted several raids deeper into modern day India. A more successful invasion came at the end of the 12th century by Muhammad of Ghor. This eventually led to the formation of the great Delhi Sultanate.
Ibn Battuta, the renowned traveler, lived for some time in India and as he was employed as a qadhi (judge) by the Sultan in Delhi. He also served as an Imam in Delhi, as a judicial official in the Maldives, and as an envoy and trader in the Malabar. Ibn Battuta was scrupulous in his observation and fascinated by the culture of the native people.
"There are certain world-wanderers," observed the Indian poet-historian ‘Isami, "who ramble the earth, neither fixing their hearts on any country nor settling for even a month in any city. But when they arrive in the land of Hindustan, they abandon their wanderings and at last settle down." Ibn Battuta stayed in India for over 7 years, a quarter of his traveling life, and it is about India to which he devoted over a fifth of his monumental book, al-Rihla’, The Travels or ‘A Gift to Those Who Contemplate the Wonders of Cities and the Marvels of Traveling’ to give its full title.
The Sultanate ushered in a period of cultural renaissance. The resulting "Indo-Muslim" fusion left lasting monuments in architecture, music, literature, and religion. Due to the sacking of Delhi in 1398 by Timur (Tamerlane), other independent Sultanates were established in Awadh, Bengal, Jaunpur, Gujarat and Malwa.