Raasay sits in the Inner Sound between the Isle of Skye and the Applecross peninsula, a sliver of an island roughly fourteen miles long, rising in moorland and old gneiss above the sea. MacLean was born there in 1911 into a family of crofters, tailors and singers - his people carried the Gaelic song tradition in their bones. He grew up hearing waulking songs and laments, the Free Presbyterian psalms of his Calvinist community, and the silence of glens emptied by the Highland Clearances a century before. Those silences shaped him. So did the visible scars on the land. From the family croft you can still see the ruined townships of north Raasay - Hallaig, Screapadal, Leac, Eyre - places his great-grandparents knew as villages and that he knew only as place names and stones. The dispossession was not abstract. It was geography you could walk to.

MacLean took a first-class degree in English at the University of Edinburgh, then taught school across Scotland - in Mull, on Skye, eventually at Plockton on the mainland opposite Raasay. In 1940 he enlisted with the Royal Signals and shipped to North Africa, where he served in the Western Desert campaign. At the Battle of El Alamein in November 1942, a landmine exploded beneath him; he survived with serious wounds and was invalided home. The war fused with the older Highland griefs in his poetry. His 1943 collection Dain do Eimhir - poems to a woman called Eimhir, drawn from the medieval Cuchulainn cycle - had already remade Scottish Gaelic verse. They were love poems, but also poems about Spain and fascism, about choosing between private feeling and the larger catastrophes pressing in. Until MacLean, modern Gaelic poetry had been mostly pastoral, religious, or lightly comic. He brought it the twentieth century.

In 1954 he wrote Hallaig, the poem that would become his signature. It begins with the line "Tha tim, am fiadh, an coille Hallaig" - Time, the deer, is in the wood of Hallaig. The cleared families are alive in the trees, walking and visiting and laughing as girls. The hunter time tries to bring them down, but the poet, watching from the window of love, holds them in the wood a little longer. The poem is short and exact and almost unbearable. In 1984 the filmmaker Timothy Neat made a documentary about MacLean built around it; the composer Peter Maxwell Davies set passages of MacLean's work in his opera The Jacobite Rising; and on Bothy Culture the Scottish musician Martyn Bennett sampled MacLean's own voice reading Hallaig, looping the Gaelic into a piece of contemporary electronic music. The poem travels because the loss it speaks of is not only Raasay's.

MacLean's influence on Gaelic was generational. The poet Aonghas MacNeacail had begun writing in English because his schooling taught him Gaelic literature was finished; reading MacLean convinced him otherwise and turned him back to his mother tongue. The Gaelic rock band Runrig once invited MacLean onstage at a concert to read his poetry to thousands of fans. He was honored at Edinburgh's Makars' Court and recognized by the Scottish Poetry Library as one of the language's modern saviors. He kept teaching, kept correcting his translations, kept living in Skye. He died in 1996, aged 85. A controversy that flared in 2000 - when excerpts from his long Cuillin poem An Cuilthionn were used by a real-estate firm to market the Black Cuillin mountains of Skye for sale - showed how completely his words had come to belong to those landscapes.

Visitors to Raasay today can take a marked path to Hallaig itself, where stone walls and lazy-bed ridges show the outline of the village that was. The trees, mostly birch and rowan, do exactly what the poem says they do. They stand where houses stood. The Sorley MacLean Trust, based on Skye, keeps his work in print and supports new readers in Gaelic and English. To read Hallaig there, with the sound of the Inner Sound below and the Cuillin smoking on the horizon, is to understand why the poem matters - not as nostalgia, but as an argument that language and land remember each other, and that as long as one survives the other has a chance.