Suttee or Sati was the custom of a widow self-immolating on her dead husband's funeral pyre.
Sometimes it was self- immolating. Other times, when the widow was reluctant to burn herself alive, she would be taken by her fellow citizens and forcefully burned to death against her will. That, I think, was the main issue.
After the British banned Suttee, several Indians protested that it was a time- honored cultural tradition (Were it in modern America, I'm sure liberal Democrats would happily repeal the ban along those lines, out of fear of seeming "Intolerant"). Sir Charles Napier, leader of the British occupation, gave a reply I'll never forget:
"Be it so. This burning of widows is your custom; prepare the funeral pile. But my nation has also a custom. When men burn women alive we hang them, and confiscate all their property. My carpenters shall therefore erect gibbets on which to hang all concerned when the widow is consumed. Let us all act according to national customs."
Yeah, the British at times abused their power in India, as nearly all outside forces occupying foreign nations sadly do at times, but they also brought an end to a lot of barbaric, genuinely evil practices such as Suttee.