They were involved in clan skirmishes with the Mackinnons, Camerons, MacDonalds and Campbells, as well as all of the Jacobite risings.

[4] The clan's rise to power began in 852 with a Papal Bull of Charter and Protection for the Iona Abbey, issued by Pope Leo IV.

The founder of the clan was a Scottish warlord descended from the Cenél Loairn kindred of Dál Riata, named Gillean of the Battle Axe (1210–1263).

[4] Gillean's son Malise mac Gilleain (from the Gaelic Maoliosa 'Servant of Jesus') was thought by some to have taken the name Gillemor in 1263 and is also said to have led his followers at the Battle of Largs in 1263.

[6] He wrote his name as "Gillemor Mcilyn, County of Perth" (indicating 'Gillemor Son of [Gil]lean') on the third Ragman Rolls of 1296,[6] swearing fealty to Edward I of England.

[4] The Macleans of Duart married into the family of John of Islay, Lord of the Isles (chief of Clan Donald).

[4] By the end of the 15th century, the Macleans owned the isles of Mull, Tiree, Islay, and Jura, as well as the mainland provinces of Knapdale and Morvern in Argyll, and Lochaber in what was later Inverness-shire.

The papal dispensation issued by Pope Urban V on 3 May of 1367 approving the already consummated marriage is the first mention of a MacLean in any official records..

Robert Stewart, the ambitious the Duke of Albany, had denied Donald's claim because he wanted Ross for himself.

The Battle of Harlaw took place near Inverurie in Aberdeenshire on 24 July 1411 against a mounted army of knights led by Alexander Stewart, Earl of Mar.

Tearlach was part of the vanguard but following this battle, he sought protection within the Clan Chattan Confederation.

The rising power of the Clan Campbell during the sixteenth century brought them into opposition with the Macleans.

[4] The match was not a happy one and Maclean took drastic action by marooning his wife on a rock in the sea, leaving her to drown.

[4][6][13] After Sir Lachlan MacLean's death in 1598, his sons took revenge on his suspected murderers, the MacDonalds, by carrying out a massacre of the people of Islay which lasted for three days.

[4] Later during the Scottish Civil War he was devoted to Charles I of England and called out his clan to fight for James Graham, 1st Marquis of Montrose who was the king's captain general.

[4][6] Archibald Campbell the 9th Earl, son of the Marquess of Argyll, invaded the Clan Maclean lands on the Isle of Mull and garrisoned Duart Castle in 1678.

Other family names associated with the clan include Auchaneson, Beath, Beaton, Black, Clanachan, Dowart, Dowie, Duart, Duie, Garvie, Gillan, Gillon, Gilzean, Hoey, Huie, Lane, Lean, Leitch, MacBeath, MacBeth, MacBheath, MacCormick, MacEachan, Macfadin, MacFadyen, Macfadzean, Macfergan, Macgeachan, MacGilvra, Macildowie, Macilduy, Macilvera, MacKlin, MacLergain, Maclergan, MacPhaiden, MacRankin, MacVeagh, MacVey, Paden, Patten, Rankin, and Rankine.

These clan badges consisted of plants and were worn in bonnets in addition to being used as a banner and attached to a pole or spear.

[23][24] In the battle of Inverkeithing, between the Royalists and Oliver Cromwell's troops, five hundred of the followers of the Laird of M'Lean were left dead on the field.

In the heat of the conflict, seven brothers of the clan sacrificed their lives in defence of their leader, Sir Hector Maclean.

This phrase has continued ever since as a proverb or watch-word when a man encounters any sudden danger that requires instant succour.