"MIRFIELD, a village in the parish of its name, in the wapentake of Askrigg and honour of Pontefract, in the west riding; is three miles from Dewsbury; pleasantly situated in a fertile, opulent and respectable neighbourhood, and is one of the favourite seats of the woollen manufacture. Its name is supposed to be derived from Moorfield or Mire field, probably at one time corresponding with its situation upon a moor or morass. The river Calder runs through the middle of the parish, Mirfield being on its north and Hopton on its southern bank. Up to the year 1261 Mirfield formed a part of the Saxon parish of Dewsbury, from which it was separated at the intercession of the Lady of Sir John Heton with the Pope, who going to mass before dawn on Christmas day, to the parish church of Dewsbury was way-laid and robbed, and her principal attendant murdered, at a place called Ravensbrook-layne. Sir John was at Rome at the time of this outrage, and entering into the feelings of his lady, procured the Pope to sanction the erection of a chapel at Dire-field, which, in process of time, became the parish church, and this ancient edifice contains some interesting monuments. The population of the parish, in 1821, was 5,041."
Note: The directory entry for Mirfield in Pigot's 1829 Directory is included with Birstall.