King's Gambit Accepted: Muzio Gambit, Brentano Defense

The King's Gambit Accepted: Muzio Gambit, Brentano Defense is a chess opening classified under ECO code C37 in the Open Games & French Defense family, beginning with 1.e4 e5 or 1.e4 e6, including the Italian Game, Ruy Lopez, and French Defense. It is reached after 5 moves: 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. Bc4 g4 5. O-O d5. The resulting position leaves white to move.