Judaism laid down a complex heavenly hierarchy, comprising seven archangels - Uriel, Raphael, Raguel, Michael, Sariel, Gabriel and Remiel - together with the seraphim and cherubim and countless lesser angels.
Seraphim, the highest-ranking angels, stand closest to the throne of God, and praise him constantly. Then come the cherubim, whose responsibilities include such special missions as expelling man from Eden and telling Mary that she would bare a son. Oh, and some believe Satan was a cherub, before his rebellion.
The numbers, size, ranking and physical (or non-physical) appearance of angels have kept theologians arguing for centuries and provided endless inspiration for artists. However, the benign beings shown in paintings bear little resemblance to the terrifying beings described in the Bible - beings that clearly had their origins in the fierce and monstrous cherubim of Assyrian mythology.