Dictionary of National Biography, 1885-1900/Sinclair, Henry (d.1418)
SINCLAIR, HENRY, second Earl of Orkney (d. 1418), admiral of Scotland, was eldest son of Henry, first earl of Orkney [q. v.] by his second wife, Jean, daughter of Walter Haliburton, lord Dirleton. He was taken prisoner at Homildon on 14 Sept. 1402 (Cal. Documents relating to Scotland, iv. 403), but received his liberty before 28 May 1405, when he witnessed a charter at Linlithgow (Exchequer Rolls, iii. 634). When the king of Scotland resolved to send the young prince (afterwards James I) for greater security to France, the Earl of Orkney was chosen to convey him thither. The probability is that they set sail on 14 Feb. 1405–6 (Burnet's Preface to Exchequer Rolls, vol. iii.). On 13 March their ship was captured by an armed English merchantman, and the young prince was brought to London, where he was detained a prisoner. Burnet (ib.) supposes that the Earl of Orkney was not detained, but returned to Orkney on a safe-conduct which he and others had on 13 Jan. 1405–6 to go to England and return to Scotland; but the Sinclair who had this pass was not the Earl of Orkney, but Sir William Sinclair of Herdmanston. It was not until 13 Sept. 1407 that the Earl of Orkney had a safe-conduct to go to Scotland on his affairs, with twelve attendants on horse and foot, on giving security ‘to re-enter his person within Durham Castle on Christmas next’ (Cal. Documents relating to Scotland, vol. iv. No. 702). On 4 Jan. 1407–8 he obtained a safe-conduct for his ship to trade with England (ib. No. 744); in 1409 he received payment for travelling to England on the affairs of the king of Scots (Exchequer Rolls, iv. 102); and in 1412 he had a safe-conduct to him and the Earl of Douglas, with fifty horsemen, to pass through England to France or Flanders (Cal. Documents relating to Scotland, vol. iv. No. 834). He is stated by Fordun to have died in 1420, one of the earliest recorded victims of influenza in Scotland, but he was dead in 1418, when a papal dispensation was granted to his widow, Egidia, granddaughter of Robert II, king of Scotland, for her marriage to Alexander Stewart, third son of the Duke of Albany. By her he had a son William, third earl of Orkney and first earl of Caithness [q. v.], and a daughter Beatrice, married to James, seventh earl of Douglas (Fordun, Chronicle).
[Authorities mentioned above; Hay's Sinclairs of Roslin.]