Sati (also called suttee) is the tradition among some Hindu societies by which a recently widowed woman either by will or by use of force or coercion commits suicide after her husband’s death.
During Mughal period, Sati was a tradition of wife burning herself on the funeral pyre of the husband. Many Mughal emperors tried to outlaw the Sati system but were not able to prevent it. Akbar and Humayun tried to stop this practice but couldn't.
Jahangir imposed strict orders and gave the death penalty to whoever favored the Sati practice of burning wives alive.
Aurangzeb was the only Mughal king to succeed in banning this deadly custom of Sati. He passed a "Farmaan" upon it and anyone who is found exercising it was penalized harshly. The Hindus at that time were dead set against this "Farmaan" and questioned it. Many Hindus who did it were executed by Aurangzeb.
Even Akbar was not able to prevent this practice of Sati. In his famous Akbar Nama, he wrote about this system and forbade it but was not able to achieve the ruling and Hindus of that time people still practiced Sati.
Sati is considered as a black spot on Hinduism and is even not approved by the scholars by then. But Aurangzeb was a firm Muslim ruler and was very strict in banning this evil practice. He was never supported by the Hindu population.
After the death of Aurangzeb in 1707 this practice reared its head and even Sikhs adopted it. Then Mughal rule weakened after his death and Hindu rule started and it was not considered to ban this practice. Then during British rule, this practiced was banned by then ruling Britishers.