Vincent van Gogh often reused his canvases to save money, and conservators suspect he painted the self-portrait on the back of a previously-completed painting. Graeme Yule/National Galleries of ScotlandThe hidden Van Gogh self-portrait was...

Julius Caesar was fatally stabbed by the Roman Senate on the Ides of March of 44 B.C.E., triggering the downfall of the Roman Republic.Wikimedia CommonsA depiction of how Julius Caesar died at the hands...