A Grand Duchy is a larger variation of a Duchy. Often, Grand Duchies are ruled over by a Grand Duke who is a member of the Royal or Imperial family, whereas a Duke need not be a relation to the ruling Noble house in most cases. Grand Duchies are somewhat similar to Principalities in this sense and some micronations are ruled as independant nations with a Grand Duke as their head, eliminating the need for a higher Monarch. Luxembourg is the last remaining independent Grand Duchy, but many micronations carry on using this system.