Lachlan Lubanach lived to a great age, but the date of his death is not known, but it must have been before 1405, for on January 28, 1405 of that year, at Dundonald, Hector was a witness to a charter confirmed by the king in favour of James Kennedy.
Lachlan Lubanach is generally regarded as the first Maclean of Duart because the oldest recorded charter in existence is in his favour. But that does not imply that he was the first possessor.
A fictionalized legendary account of Lachlan's marriage and coming in possession of Duart was given by Fitzroy Maclean in The Isles of The Sea.
This article incorporates text from A history of the clan Mac Lean from its first settlement at Duard Castle, in the Isle of Mull, to the present period: including a genealogical account of some of the principal families together with their heraldry, legends, superstitions, etc, by John Patterson MacLean, a publication from 1889 now in the public domain in the United States.
^ ab"Duart Castle". Duart Castle. Retrieved 2009-03-06. "In 1350 Lachlan Lubanach, the 5th Chief, married Mary Macdonald, the daughter of the Lord of the Isles and she was given Duart as her dowry."
^ ab"One Clan, Two Families". Clan Maclean. Retrieved 2009-03-24. "Lachlan Lubanach and his brother Hector Reaganach were, respectively, the progenitors of the Duart and Lochbuie families but how these two acquired land in Mull is not known for certain, but they are certainly the first Macleans on the island.... On 13 May 1367, Lachlan MacGilli eoin received a mandate from the pope to marry Mary, the daughter of John de Yle, and, given the supreme importance of the matrilineal inheritance (inheritance through the female line), this gave Lachlan a particularly powerful link to his immediate overlord."
^ abcdMacLean, John Patterson (1889). A History of the Clan MacLean from Its First Settlement at Duard Castle, in the Isle of Mull, to the Present Period: Including a Genealogical Account of Some of the Principal Families Together with Their Heraldry, Legends, Superstitions, Etc.. R. Clarke & Company. "Lachlan LQbanach. Fifth Chief of MacLean. The date of the beginning of Lachainn Lubanach as fifth chief of MacLean, and successor to his father, John Dubh, is not known. 'It, in all probability, antedates 1365. His feuds with the MacDougalls and Camerons were during that period after he became chief. John, First Lord of the Isles, lived until 1386, when he was succeeded by his son Donald. Under the Second Lord of the Isles, Lachlan took due precaution to have his lands confirmed by charter, which occurred in 1390, as already noticed on page 29. He had five sons, Hector, his successor in Duard, John, Lachlan, Neil, and Somerled. He lived to a great age; the date of his death is not known, but it must have been before 1405, for on January 28th, of that year, at Dundonald, Hector was a witness to a charter confirmed by the king in favor of James Kennedy. [Registrum Magni Sigilli, Lib. IV., No. 56.] Lachlan Lubanach is generally regarded as the first MacLean of Duard. This is doubtless because the oldest recorded charter in existence is in his favour. But that does not imply that he was the first possessor."