Formed in Los Angeles, CA, in 2003, Donnybrook! went through various lineup changes before settling on vocalists Dre Stewart and Bo Thomson, guitarists Martin Stewart and Pat Burgess, bassist Danny Banura, and drummer Art Banura.
Donnybrook! are strict hardcore purists who released There's No Love for the Insincere EP in 2004 through 1917 Records, after which Thomson left the band. They also released a split with Piece by Piece that same year. Hooking up with Hand of Hope, the band next release was the 2005 album Lions in This Game.