He was born in late 1289, the same year as his father Donnchadh III's murder. He therefore inherited the Mormaerdom as a baby. He was so young that the honour of crowning John Balliol – normally the hereditary right of the Mormaer of Fife – was delegated to a knight, namely John de St. John. He also missed the crowning of Robert the Bruce, owing to his captivity in England. Robert was forced to call upon Donnchadh's sister, Isabella, to officiate in his absence.
Donnchadh's initial support for Robert has been doubted,[2] but in 1315, a year after the Battle of Bannockburn, he resigned his Mormaerdom to King Robert for a regrant.[3] The agreement with Robert ensured that the Mormaerdom of Fife would not be held by the king, and that the arms of Fife should always be unique from the similar royal arms. If Donnchadh were to die childless, King Robert would grant it to someone, by default Alan of Menteith.[4] This was because Donnchadh's wife was in the custody of the English, and there was obviously some pressure from the men of Fife to retain their own regional ruler. He was present at the negotiations which led to the Treaty of Edinburgh-Northampton, and was a signatory to the Declaration of Arbroath.[5]
The Earl of Fife fought with the Bruce loyalists at the Battle of Dupplin Moor where, he being made prisoner, changed sides and, with William Sinclair, Bishop of Dunkeld, a great adherent of Robert the Bruce, crowned Edward Balliol King of Scots at Scone on 24 September 1332.[6] The following year, on 19 July 1333, he fought with the Scottish army at the Battle of Halidon Hill, where he was again captured.
In 1306, Donnchadh married Mary de Monthermer, a granddaughter of Edward I of England. He died in 1353 without any male heirs. He is important because he was the last male Gaelic ruler of Fife. He was succeeded in his mormaerdom by his daughter Isabella, who married four times:[citation needed]
William Ramsay of Colluthie. He succeeded as Earl of Fife, de iure uxoris. William and Isabella had a daughter named Elizabeth Ramsey. Alternatively she may have been married to William Felton.[7]
^Called Donnchad[h] IV by Dauvit Broun, "Anglo-French Acculturation", p. 138; called Duncan (IV) Macduff and ninth earl of Fife by Andrew McDonald, "Macduff family, earls of Fife (per. c.1095–1371)", Oxford Dictionary of National Biography, Oxford University Press, 2004 , accessed 8 Sept 2007; called Duncan (IV) by Bannerman, "Macduff of Fife", p. 33; in Angus, William, editor, 'Miscellaneous Charters 1315-1401' in Miscellany of The Scottish History Society, volume 5, Edinburgh, 1933: 25, where he is given in a latin charter as Duncanus comes de Fyff, and p.63 where he is given as Duncanus comes de Fyff, and where the modern author calls him the tenth Earl of Fife. The number of earls of Fife before Donnchadh IV is not actually known; many older numberings include Ethelred, lay abbot of Dunkeld; this is based on a mistake produced by translation problems from a late 11th-century Gaelic charter; see Bannerman, "Macduff of Fife", p. 30, n. 3. There were at least two, and almost certainly more, earls of Fife before either Ethelred or Causantín; see Bannerman, "Macduff of Fife", passim.
^In Stephen Boardman's book The Early Stewart Kings, p. 13, Boardman gives the account of the contemporary English chronicler Sir Thomas Gray who declared that Donnchadh "had forfeited the earldom to the crown during the reign of Robert I for the murder of an esquire named Michael Beaton and had received it back as a male entail which had reverted to the crown on Duncan's [Donnchadh's] death."
^Bain, FSA (Scot)., Joseph, The Edwards in Scotland, Edinburgh, 1901, p. 84.
^Andy King, Michael A. Penman, England and Scotland in the fourteenth century: new perspectives, page 119. According to the Scalacronica Isabella was arranged to marry Robert Stewart, but married William Felton who had been in charge of her wardship.