Although a Yorkist victory, Sir James and his father, along with Warwick's brother John Neville were captured after the battle, at Acton Bridge, and sent to Chester Castle.

[9] Following the victory of Edward IV at the Battle of Towton on Palm Sunday, 29 March the next year, Sir James was made the King's escheator for Yorkshire.

[13] When James's brother Sir John Harrington fell at Wakefield, he left as his heirs his two daughters, Elizabeth and Anne,[14] who were four and five years old at the time,[15] which meant their wardship was automatically in the hands of the Crown to dispense.

Edward duly did so, to Thomas, Lord Stanley in November 1461, but James and his brother Sir Robert, in attempt to keep the inheritance for the family, effectively disallowed the King's grant and imprisoned (or, kept in custody) the two girls, as Anthony Goodman noted, "contrary to their will, in divers places."

[18] In October 1466, Stanley obtained a grant to sue in the King's Court, but the matter was not dealt with until 1468, when a commission found against Harrington[19] and he and his brother were committed- "temporarily", Ross noted- to the Fleet Prison.

[22] When Edward returned from exile on 14 March 1471, Harrington was one of the first (and one of the few) northern knights to openly join him, meeting him at Doncaster (or possibly Nottingham)[23] with 600 men-at-arms and Sir William Parr.

[29] He was appointed to a Commission of the peace for the West Riding of Yorkshire the same year;[30] the most obvious reason for this being, Ross suggests, was that they were still "trusted Yorkist servants"[31] and the King had a reluctance to alienate his own supporters.

[45] However, the Harrington family tradition holds that he died there, and the later Ballad of Bosworth Field claimed he, with other northern knights, brought "a mighty many" there;[46] he was certainly excluded from the general pardon of 1486 and attainted in 1487.

According to Rosemary Horrox, there are no more references to any "James Harrington", except his Cambridge-educated nephew[49] who fought for the rebel earl of Lincoln at the Battle of Stoke, was attainted and then pardoned before becoming Dean of York and dying there in 1512.

[56] His widow Elizabeth wrote to her second husband some time after Bosworth expressing the belief that the boy had been poisoned ("a little before [or] or more probably a little after" that battle, reports Baldwin) by her ex-brother-in-law Edward Stanley, who, having received James's estates from his attainder, wished to ensure that John would not be able to seek its reversal.