The Battle of Marston Moor, which is located near York in northern England, was a decisive engagement in the English Civil War. The Royalist side was soundly defeated by a combined force of Scots Covenanters and Parliamentarians. It was a serious blow to the Royalist side, which more or less abandoned the northern part of the country thereafter.
Oliver Cromwell, at the time little-known, distinguished himself in this battle. He commanded the Ironsides Cavalry, and his leadership and the discipline of his troops were both acknowledged as key factors in the victory. From here, Cromwell’s star would only rise.
By John Barker – http://www.bridgemanartondemand.com/art/154979/Battle_of_Marston_Moor_1644, Public Domain, Link
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