Once it was denounced as a display of tribal triumphalism, a day when bigoted Orangemen asserted their supremacy over Catholics in Northern Ireland – and sometimes sparked off ugly large-scale violence.
But when the Orange Order takes to the streets today for its annual 12th of July marches, many will be keenly watching for signs of change in its ancient rituals.
The Order has been working with tourist authorities on both sides of the border to smooth the 12th's hard edges and present it as a welcoming occasion, as befits the new Northern Ireland governed by a Unionist-republican coalition.
The Orange Order is noted for its devotion to the past, coupled with an anti-Catholic reputation, yet in the past few years new thinking has been evident among some of its leaders.
The theory – still in its infancy – is that its hard image can be softened to incorporate an element of cultural expression that would make the marching season an attraction rather than something to be avoided.
The proposition is to change a tourism negative into a positive. In addition to the marching, there is to be more entertainment and pageantry and family-orientated events, in particular at four "flagship" venues.
David Hume, the Order's director of services, said: "We cannot thank the tourist authorities enough. They have shown us their research and made very many useful suggestions which we have taken on board."
This year is not expected to witness a sea-change in the parades which criss-cross Northern Ireland, for the strength of feelings within the Order and in both parts of the wider community run deep.
There is, for example, no expectation that substantial numbers of Catholics will attend or even spectate at what most of them regard as events hostile to both their religion and their politics. They can in general be expected to give a wide berth to today's parades. Many have already done so by scheduling their holidays to coincide with the 12th and, in what has become an annual evacuation, are already in Spain, the Irish Republic and elsewhere.
This habit of summer flight became pronounced over the past decade when disputed marches earlier in July, centring on Drumcree in the Co Armagh town of Portadown, produced widespread rioting and deaths.
The marching issue now generates far less heat than it did, since the Portadown march has been banned for more than 10 years in a row. This year Drumcree passed off without incident. Other parades do go through Catholic areas, but they generally following dialogue and local agreements with residents.
This phase of the re-branding of Orangeism is aimed at attracting tourists from abroad rather than enticing local Catholics to participate in what has become known as "Orangefest".
Yet even here there are signs of the beginning of a thaw, with previously unthinkable encounters taking place. Earlier this year, Portadown Orangemen held separate meetings with Ireland's Catholic cardinal and with Gerry Adams, president of Sinn Fein.
Orange headquarters took a dim view of the Adams meeting, however, and also takes a dim view of the overall peace process, objecting to the presence in government of Sinn Fein.
One of the themes of speeches at Orange venues today will be the complaint that Catholics have benefited much more from the peace process than have Protestants. At the same time, observers are watching as change slowly ripples through an organisation famously resistant to change.