The Ambassadors is a painting by Hans Holbein the Younger made 1533. It depicts Jean de Dinteville, French ambassador to London at the time, and Georges de Selve, a French scholar, diplomat and a member of the clergy. The painting was presumably commissioned by Dinteville. He wanted to give it to Georges de Selve as a sign of friendship.
The Anamorphic Skull
The most prominent feature of the painting is a distorted skull in front of the characters. Many scholars theorized that it was an intentional thing add by the painter. They believe that Dinteville's motto was memento mori, meaning "Remember thou shalt die". However, the truth is different. Holbein made the painting without the skull and it was delivered to Dinteville without. Then it waited in one of the rooms of Dinteville's house for being transported to de Selve.
Through interrogating Dinteville's servants, an enemy of both Dinteville and de Selve learnt of the painiting. He managed to get inside the house during the night and performed a blood magic spell. He used the painting as an intermediary to kill both men at the same time. The appearance of the anamorphic skull is a side effect of that spell.