Stalin died on March 5, 1953. It was officially said to be because of a stroke. In 2003, however, a group of Russian and American historians said that Stalin had been poisoned with powerful rat poison warfarin, possibly by the men who took over the government after Stalin died. Led by Lavrentiy Beria, these were Vyacheslav Molotov and Georgy Malenkov. Nikita Krushchev later began a process called "De-Stalinization", which meant taking apart much of the political system that Stalin made. Stalin was denounced as a tyrant. After outsmarting and defeating his rivals, Krushchev established a personal control over the government comparable to Stalin's own, even if he never went as far in murdering millions of people.