Does anyone know when or how was ice cream actually invented?

Ice cream probably developed when people started to milk goats, cows, buffallo and any other animal [mammal] that produces milk in quantity for human and animal consumption. It is just frozen milk but not the watery kind that we drink in our tea. I think it is the froth that forms on top of the milk and this is scooped off, frozen for icecream, or used to make butter. then they started to add flavour.