Badrachalam History: Legend has it that, Lord Maha Vishnu again manifested Himself as Lord Rama, long after His Ramavatara, in order to fulfil a promise He made to His devotee Bhadragiri (a boon child of Meru- the Lord of mountains and Menaka). It is said that Bhadra (or Bhadragiri) performed intense penance at the bank of Godavari, for centuries, to get the glimpse of Lord Rama and reside over him. But Lord Rama promised him that He would come on His way back after finding Goddess Sita. But due to some reasons Lord Rama could not keep up His promise. It was then that Lord Maha Vishnu took the form of Vaikuntha Rama and descended on the Earth to make His devotee's desire come true.
The Lord, along with His consort Sita and brother Lakshmana came down to the place where Bhadra took the form of a hill - Bhadragiri. One of the rare forms of Lord Rama having four hands, armed with Shank and Panchajanya in His right hand and Sudharshana Chakra and Dhanurbhana (bow and arrow) in His left hand, is seen in this temple. These deities settled on the head of Bhadra (i.e., on the peak of the mountain) and hence this came to be known as 'Bhadra'- Achalam (hill) or 'Bhadrachalam'.