Ironsides

Ironsides, Cromwell's troopers, a thousand strong, and raised by him in the Eastern counties of England, so called at first from the invincibility displayed by them at Marston Moor; were selected by Cromwell “as men,” he says, “that had the fear of God before them, and made conscience of what they did.... They were never beaten,” he adds, “and wherever they were engaged against the enemy, they beat continually.”

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Ironclads * Irony
[wait for the fun]
Irkutsk
Irmin
Iron Age
Iron City
Iron Crown
Iron Duke
Iron Gate
Iron Hand
Iron Mask, Man with the
Ironclads
Ironsides
Irony
Irony, Socratic
Iroquois
Irreducible Case
Irtish
Irving, Edward
Irving, Sir Henry
Irving, Washington
Irvingites
Isaac

Nearby

Ironsides in Brewer’s Dictionary of Phrase & Fable

Links here from Chalmers

Cromwell, Oliver