Chess Opening Theory/1. e4/1...e5/2. f4/2...exf4/3. Bc4/3...Qh4/4. Kf1

= King's Bishop Gambit Accepted =

4. Kf1
White now cannot castle, but does have the chance to obtain a lead in development via Nf3, attacking the queen.

Theory table
'''1. e4 e5 2.f4 exf4 3.Bc4 Qh4+ 4. Kf1'''


 * Modern Chess Openings: MCO-14. 1999. Nick de Firmian, Walter Korn. ISBN 0-8129-3084-3.