Blake, James (p.1560–1635), alias ‘Caddell’, ‘Blackcaddell’, ‘Blague’, and ‘Diego de Blac(c)adell’, merchant, soldier, and double agent, was born in Galway, second son of Walter Blake (d. 1573) and his wife Juliana (née Browne). The aliases derive from variants on ‘Blake’ and the family's origins in the Cadells of Wales. His grandfather and brothers served as mayors of Galway, and his elder brother, Valentine (qv) (1560–1634), was created a baronet 10 July 1622.
James Blake came to government notice late in 1587 as one of several Irish merchants importing goods from Spain. In 1588 he made contacts with Spanish officials through salvaging material from the wrecks of Armada ships on the Irish coast; he was consequently imprisoned by the English government in Ireland. He may have gone to Spain in 1589 by way of Scotland and Flanders; in 1594 he was at the court of Philip II, fought subsequently on the Spanish side in Brittany, and was captured there by Sir John Norris (qv). Norris used Blake as an agent but found him unreliable, and wrote in 1595 to Cecil that ‘the matter of Captain Cadell [sic] of Galway may put the Spaniards out of taste with trusting to the Irish’ (quoted in Walsh, 389). William Paul, an English official in Ulster who met Blake about this time, described him as ‘a cross intelligencer [double agent], but means may make him firm’ (ibid., 390). In 1597 Blake wrote to Philip from Ireland, offering help in the event of a Spanish landing; and in August 1602 he presented to the Spanish government detailed written proposals for an expedition to Galway. Between these two approaches, however, he had offered the English government his services in infiltrating the rebels in Ireland, and had separately been proposed by the mayor of Galway as leader of a force against piracy. He is best known for having been suspected of poisoning Red Hugh O'Donnell (qv) (Aodh Ruadh Ó Domhnaill), as he had approached Sir George Carew (qv) shortly beforehand with an offer to kill Ó Domhnaill. Blake and his servant were interrogated after the death, without – apparently – being suspected of complicity. Blake died at Galway 20 February 1635 and was buried in the nearby abbey of St Francis.
He married (date unknown) Margery, daughter of Dominick Browne, alderman of Galway; they had one son and one daughter.