Dictionary of Medieval Names
from European Sources

Marmaduke m. Possibly Old Irish máel 'bald, tonsured' + Old Irish Máedoc 'of Máedoc', the name of a 6th-7th C Irish saint.

Spellings like Marmaduke were virtually restricted to North Yorkshire, England before the 16th C; if the origin of the name really is Old Irish (as Withycombe s.n. Marmaduke suggests), then this is one of the rare instances of a name which was borrowed from Irish into English, rather than the other way around.

1566 Marmaduci (gen) Reg-KirkElla p. 5; 1569 Marmaduci (gen) ibid. p. 7; 1579 Marmaducus (nom) ibid. p. 9; 1580 Marmaducus (nom) ibid. p. 10; 1585 Marmoduci (gen) RegBeb p. 137
1245–1250[1586] Marmaduk Glover 129, Marmaduke ibid. 214
Early Modern English
1557 Marmaduke PRThirsk p. 2; 1565 Marmaduke CAmar-vol1 p. 2; 1581 Marmaduke RegPat p. 2; 1592 Marmeduke DEmar-vol1 p. 86; 1593 Marmaduke DEmar-vol2 p. 27; 1595 Maraduke CAmar-vol1 p. 5
Cite as: A. Brown, S.L. Uckelman. "Marmaduke". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2023, no. 1. http://dmnes.org/2023/1/name/Marmaduke.