Some of the places in Sindh have been inhabited as early as the 3rd millennium BC. A large number of Indus valley sites have been found in Sindh. Sindh was ruled by local Hindu and Buddhist rulers until 712 CE, when it was invaded by the Arabs and incorporated into part of the Umayyad Caliphate, resulting in widespread conversions to Islam. However, a substantial number of Sindhis still retain their Hindu beliefs intertwined with elements of Sikhism, and are thus often regarded as simultaneously Hindu and Sehajdhari Sikh.
Sindhi culture is highly influenced by Sufi doctrines and principles. Some of the popular cultural icons are Raja Dahir, Shah Abdul Latif Bhitai, Lal Shahbaz Qalandar, Jhulelal and Sachal Sarmast.
Following the partition of India in 1947, most Hindu and Sikh Sindhis fled to modern-day India and other parts of the world, though, as of 1998, Hindus still constituted about 6% of the total Sindhi population in Pakistan.
There are 35 Million Sindhis living in Pakistan (33.5 million in sindh, and 1.5 million in other provinces). Karachi is the largest Sindhi Speaking enclave in the world, with 3.5-4.5 Million Sindhis. Hyderabad,Sindh ranks 2nd with 1-1.5 Million Sindhis,Larkana ranks 3rd with 500,000 Sindhis,and Sukkur ranks 4th with 350.000 Sindhis. 12.5% Sindhis in Pakistan are Hindus,Mostly Living in Urban areas like Karachi,Hyderabad,Sukkur,Mirpur khas. Hyderabd is the largest centre of Sindhi Hindus with 350.000-500.000.