According to Valmiki Ramayana, Devarata Janaka received the famous divine bow of Lord Shiva named as "Pinaka" for its safe-keeping.
In Ramayana, Shreedwaja Janaka father of Sita, narrated the story of the divine bow Pinaka at the Swayamvar Sabha of Lord Rama and Goddess Sita in Mithila.
He told that at the time of the destruction of Daksha Yagya, Lord Shiva told the Devatas, "In your eagerness to participate in the Yagya, you could not take my share.
Lord Shiva then gifted them this bow which they later gave to our ancestor Devarata.
[2][4][5] In the text Mithila Mahatmya which is a section of larger text Brihadvishnupurana, Mithila has been described as the land of Devarata Janaka in the Shloka number 48.