Surely there can be few more famous regiments of Horse from the English Civil War than Cromwell (later Fairfax's) "Ironsides". From a troop at Edgehill it grew to a double sized regiment and more over time.
They are known to have worn red coats. I have used Orange/Tawney sashes for the officers etc, although white sashes may have been more likely, especially later in the ECW.
The "coronet" carried by this unity is that of Captain Robert Swallow's troop. The inscription reads "Ascendia Cura Sionis" (? possibly "Incendia") - "Burning with the Care of Zion."
From 1642 to 1645 the regiment saw extensive action, including the battles of Grantham, Gainsborough, Winceby, Marston Moor, and 2nd Newbury.
I didn't mirror image this flag due to the effect upon the text.