Who was Liber?

Liber (the free one) or Liber Pater (the free Father) was the god of viticulture and wine, fertility and freedom. He was a patron god of the plebeians and was part of their Aventine Triad (also referred to as the plebeian Triad or the agricultural Triad). This is a modern term for the joint cult of the Roman deities Ceres, Liber and Libera. The festival in his honour, the Liberalia was associated with free speech and the rights attached to coming of age. His cult became associated with Bacchus and his Greek equivalent Dionysus.