Dashavatara refers to the ten principal Avatars. In Vaishnava philosophy, an Avatar most commonly refers to the 'descent' and dasa refers to 'ten' in number. The ten most famous incarnations of Vishnu or sometimes Krishna are collectively known as the Dashavatara. This list is included in the Garuda Purana (1.86.10-11) and denotes those avatars most prominent in terms of their influence on human society.
Vamana, the dwarf, appeared in the Treta Yuga. The fourth lineal descendant of Hiranyakashyap, named Bali, through his devotion and penance defeated Indra, the god of firmament, humbled other gods and extended his authority over the three worlds. All the gods appealed to Lord Vishnu for protection and He became manifest in His Dwarf Avatar of Vaman for the purpose of restraining Bali.
