From what I've been able to gather in my research, the name de la Roche, de Roche, Roche, da Rocha, Rocha, originates from the family who owned Castle de Roche, in Pembrokeshire, Wales. There was a Godebert "the Fleming" de Ros who is believed to have either accompanied William the Conqueror to Britain, or it may possibly have been his father who came over with the invasion force.