In a stunning move, House Speaker John Boehner informed fellow Republicans on Friday that he would resign from Congress at the end of October, stepping aside in the face of hardline conservative opposition that threatened an institutional crisis.

The 13-term Ohio Republican shocked his GOP caucus early Friday morning when he announced his decision in a closed-door session. It came one day after a high point of Boehner's congressional career, a historic speech by Pope Francis to Congress at Boehner's request.