Spirits in Vodou are known as Loa; Catholic Saints lithographs are used to represent them. During slavery in Haiti, white french masters forbade the slaves from pursuing Vodou as a religion and anyone caught practicing any religion other than Catholicism were severely punished. The slaves, still deeply attached to their African roots, were obliged to use Catholic Saint Image during Vodou ceremonies, pretending to be praying to them while deep in their heart they were praying to their African gods. This is the main characteristic that differentiate the Vodou that is practiced in Haiti and in Africa. Over 400 years have passed, but the tradition strangely still remain today; it is so deeply rooted in the religion that it is almost impossible to even imagine Haitian Vodou without the representation of the Loas with Catholic Saints' images.