What was the class system the Celts lived by

There were four classes in Celtic society, each contributing something to the others in return for a service from that class. The classes were as follows; Chiefs, Nobles, Druids and Bards (considered one class), and the peasants. The Chief gave land to the peasants, money to the nobles, and rights of their position to theLearned(Druids,Bards). The Nobles gave protection to the peasants and Learned, and military service to the Chief. The Learned gave religious rites to all, and the bards sang praises to the Chief and Nobles, and gave knowledge,(limited, of course, this was the source of their power in the society) to all. The peasants merely worked the land, providing labor and food to the society. Women could become any of these.