Tyrrell's father was beheaded on Tower Hill on 23 February 1462, together with Sir Thomas Tuddenham and John Montgomery. John de Vere, 12th Earl of Oxford, and his eldest son and heir, Aubrey, were beheaded on 26 February and 20 February, respectively, after the discovery of an alleged plot to murder Edward IV.

SIR JAMES TYRELL is one of the most notorious figures of the later fifteenth century yet his character, and his antecedents and connections, remain relatively obscure. It is hoped that the following article will go some way to remedy this. The Tyrell genealogy for the second half of the fifteenth century is made more difficult by the number of Tyrell men bearing the same Christian names, and the accompany table will, it is hoped, make clear the family relationships here described.

Sir John Tyrell of Heron, Essex (d. 1437), a distinguished man, had been Speaker, Treasurer of the Household, and Sheriff of Suffolk, and of Hertfordshire. He had married Alice, daughter of William Coggeshall and granddaughter of the celebrated English condottiere, Sir John Hawkwood of Sible Hedingham, Essex, known in Italy as Giovanni Acuto. Hawkwood was twice married. The name of his first wife, the mother of Coggeshall’s wife Antiocha (or Mary), is not recorded, but she was possibly a Brandolim' of Bagnacavallo. Footnote 1 She was dead by 1377, when Hawkwood married Donnina (or Aufricia), one of the bastard daughters of Bernabb Visconti, Duke of Milan, by Donnina di Leone Porto, a Milanese noblewoman. Of Bernabb’s legitimate daughters, Footnote 2 one, Lucia, was married to Thomas Holland, Earl of Kent, another, Violanta (or Yolanda), married Lionel, Duke of Clarence.