Brewer's: Loose-coat Field
The battle of Stamford in 1470. So called because the men under Lord Wells, being attacked by the Yorkists, threw off their coats that they might flee the faster.
Cast off their country's coats to haste their speed away: Which `Loose-coat Field' is called e'en to this day.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894