Janaka was an ancient Hindu king of Videha which was located in Mithila region, approximately in the 8th or 7th century BC. The rulers of the Videha kingdom were called Janakas. He also appears in the epic Ramayana as a father of Sita. His original name was Siradhvaja and he had a brother named Kushadhvaja. His father's name was Hrasvaroman, a descendant of the king Nimi.

Videha was an ancient Indo-Aryan tribe of north-eastern Indian subcontinent whose existence is attested during the Iron Age. The population of Videha, the Vaidehas, were initially organised into a monarchy but later became a gaṇasaṅgha, presently referred to as the Videha Republic, which was part of the larger Vajjika League.