“The Fighting Prince of Donegal,” 1966 ... the year I was born.
Must've been a thing back then.
Also in the mid-'Sixties there was a book "Pirate Queen" about Grace O'Malley, an Irish chieftain who also fought the Elizabethan English.
The fact that I remember it shows that I liked it a lot!
I loved that too
The turret fight scene
The prince in green
All from memory