There are numerous differing etymologies attributed to the name. The name was first introduced into England by Bretons who took part in the Norman Invasion in the 11th century. Alan is also an Old Breton personal name (from which the modern English Alan is ultimately derived), as well as being a Norman French name. In Breton, Alan is a colloquial term for a fox and may originally have meant "deer", making it cognate with Old Welsh Alan. There are numerous variations of the name in English. The variants Allan and Allen are generally considered to be derived from the surnames Allan and Allen. Alanus de Rupe was a Roman Catholic theologian noted for his views on prayer. Some writers claim him as a native of Germany, though Cornelius Sneek, assures us that he was born in Brittany.