Seeta was known to lift the Shiva’s bow during childhood.

It was therefore essential for Janak to find a groom who can at least match her prowess.

The inability of other kings to lift the Shiva’s bow became the reason that Sita wasn’t getting married and that worried Janak.

The disappointed kings who failed even tried to wage war against her father Janak.

When Ram came to Mithila there was no Swayamvar.

It was Vishwamitra, who before going to Mithila, told Rama that he would be showing one insuperable bow of Lord Shiva kept over there.

Rama took up the challenge and easily lifted the Shiva's bow.

Janak was overjoyed, and Sita and Rama were happily married.