This piece is a replica of a mask used in theaters. Actors were wearing such masks while interpreting their roles during the 5th c. BC. The masks were worn for many reasons, such as: visibility in the big theaters, acoustic assistance, possibility for one actor to interpret many roles and possibility to represent each character's features.
None of the ancient Greek masks themselves exist because they were made of wood, linen and cork, materials that deteriorated easily with the time. We only know what they looked like from painters and sculptors that copied them.
Dionysus or Bacchus (according to the Romans) was the Greek God of wine and fertility. He was represented either as a bearded man, or as a beast or as a delicate young person. He was wandering through many lands, teaching the art of wine culture and the mysteries of his cult.
Many festivals were held in his honor, and it was believed that he could liberate people through wine and ecstatic frenzy, and give them divine creativity. Thus, Dionysus has been considered as the patron of the arts.