Sati was a ritual practiced in some parts of India until the twentieth century. It could take various forms, and in some cases, was largely symbolic, but generally speaking, it was the practice of self-immolation by widows on the funeral pyres of their deceased husbands. Historians dispute its origins, with some pointing to ancient Hindu religious texts, and others to the practice of putting women and children to death rather than surrendering to conquering enemies. In any case, it was most widely practiced among aristocratic classes in Bengal and Rajputana. It is a difficult practice for historians and anthropologists to interpret, as most existing sources came from European observers, or Indian males. European observers, in particular, tended to be either shocked by the spectacle, or full of praise for the loyalty of the widow. Either way, they offer little insight as to the significance of the practice in Indian culture. A campaign to ban sati commenced under the influence of the East India Company in the nineteenth century, but there are documented instances of the ritual throughout the imperial period.