Short answers, pulled from the story.
The Cheraman Juma Mosque was constructed in 629 CE by the last ruler of the Chera dynasty known as the Cheraman Perumal. This structure stands in Kodungallur, Kerala, and represents the first mosque in India.
A governor of Bahrain led the first military incursion into the subcontinent in 636 CE targeting the Makran region. This operation was followed by attacks on Sindh in 649 CE by Al-Hakim ibn Jabalah al-Abdi.
Sufi mystics spread Islam across the subcontinent by integrating agricultural settlements with larger cultures and receiving grants to clear forests. They played a crucial role in West Punjab and East Bengal where the majority of the subcontinent's Muslim population eventually settled.
The Faraizi movement in rural Bengal aimed to remove indigenous folk practices and commit the population exclusively to Allah and Muhammad. This movement was part of a broader trend of Islamic reform that sought to align South Asian Islam with the teachings of the Quran.
The partition of India occurred in 1947 and resulted in the concentration of Muslim majorities in the northwest and northeast regions of the subcontinent. The creation of Pakistan and Bangladesh in 1971 further reshaped the demographic landscape of the region.