Brexit has reopened old wounds and old questions, making Northern Ireland wary of its anniversaries. This year is the centenary of the Anglo-Irish war that led to the partitioning of Ireland and the 50th anniversary of the start of the Troubles – historical events that now carry the air of unfinished business amid renewed contention over the border and national identity.

Power sharing between nationalists and unionists has collapsed. Sinn Féin seeks a referendum on Irish unification, while the Democratic Unionist party seeks to unravel the European Union membership that is threaded into the peace process. The Good Friday agreement – signed 21 years ago last week – is wilting.

This weekend, however, Northern Ireland is able to celebrate one anniversary that transcends borders and unites political foes. It would have been Seamus Heaney’s 80th birthday. “It’s a time for celebration of the man – of everything in his life and work,” said Glenn Patterson, the novelist. “Seamus was endlessly inquiring and endlessly engaged. His life teaches us to not see geography as a barrier.”

Actors, writers and musicians gathered on Saturday in the village of Bellaghy, near the late poet’s birthplace and childhood home in County Derry, to celebrate the anniversary.

HomePlace, a visitor centre dedicated to the Nobel laureate, organised performances by the Codetta choir, the US composer Mohammed Fairouz, and the Serbian viola player Milena Simovic, along with readings by the Line of Duty actor Adrian Dunbar.

Heaney, who died aged 74 in 2013, was from a Catholic and nationalist background, an identity manifest in his famous line: “Be advised my passport’s green. No glass of ours was ever raised to toast the Queen”. But poems like Death of a Naturalist, Digging and Mid-Term Break tapped into a humanity which cut across the political divide and enchanted readers around the world.

After a week when the UK’s stalled attempt to leave the European Union pitted nationalists against unionists, leaders from both sides found reason to quote Heaney.

Jeffrey Donaldson, the DUP MP, tweeted condolences to RTE’s Brussels correspondent, Tony Connelly, upon the death of his mother by citing from the poem Clearances: “I remembered her head bent towards my head, Her breath in mine, our fluent dipping knives – Never closer the whole rest of our lives.” And the former Sinn Féin leader, Gerry Adams, re-tweeted an excerpt from the poem North. “Compose in darkness. Expect aurora borealis in the long foray but no cascade of light.”

Heaney grew up amid profound divisions – Catholic and Protestant, nationalist and unionist, south and north, Irish and British, Gaelic and English – but found connection and metaphor in the rhythms, sights and smells of a rural childhood, as expressed in an oft-quoted line from his 1987 volume The Haw Lantern: “Two buckets were easier carried than one/I grew up in between.”

Hailed as Ireland’s greatest poet since WB Yeats, Heaney won the 1995 Nobel prize for literature for “works of lyrical beauty and ethical depth”. Many of his poems dealt with borders between farms, counties and countries, but they can offer respite from angst over Brexit and the backstop, said Brian McCormick, a nephew of Heaney who manages HomePlace.

“When people step through our doors, whatever is going on in the outside world, they can leave it. We do become an oasis. We’re seen as a neutral space. There’s a tranquility within the building.”

The centre, built on the site of a fortified former Royal Ulster Constabulary station, features photos, personal artefacts and recordings of Heaney, who is buried in a nearby graveyard. The DUP leader, Arlene Foster, and the then Sinn Féin leader, Martin McGuinness, attended its opening in 2016, a rare display of bipartisanship before power-sharing collapsed. The centre has drawn more than 75,000 visitors and revived Bellaghy, which now boasts a Poets Corner cafe and a housing development called Poets Walk. It seems inoculated to Northern Ireland’s political toxicity.

Bellaghy is seen as a nationalist stronghold – home of IRA hunger strikers and a leader of the INLA paramilitary group. Sinn Féin election posters advocating Irish unity adorn lampposts. “My family wouldn’t shop in this village on principle,” said one man, a Presbyterian. “But our church group visits HomePlace. Heaney is just as much ours as theirs.”

Pauline Scullion, 54, a Bellaghy resident, agreed. “Everyone can buy into Heaney. It doesn’t matter who you are or what you are.” Her husband, Shane Hughes, 53, says the centre casts a spell over visitors. “It’s about literature. I’ve never heard anyone in this place mention Brexit.”

Heaney’s open personality touched people as much as his work, said Patterson, who runs the Seamus Heaney Centre for Poetry at Queen’s University Belfast. “One of the things that set him apart was the degree to which he was able to forge that personal connection.”

The centre features videos of Prince Charles, Stephen Fry, Bono and others reciting Heaney poems. Bill Clinton recites a segment from The Cure at Troy, a poem widely cited in the glow of the 1998 Good Friday agreement:

“History says, Don’t hope
On this side of the grave.
But then, once in a lifetime
The longed-for tidal wave
Of justice can rise up,
And hope and history rhyme.”