The six-mile march from central Belfast to Stormont marked the 100th anniversary of the Ulster Covenant, to oppose Home Rule for Ireland in 1912 and passed peacefully, despite media attempts to incite violence, a great triumph for the Posse.
A century ago, the signing of the document laid the foundations for the partition of Ireland and the formation of Northern Ireland a decade later.
Northern Ireland’s Chief Constable Matt Baggott said the parade had been been “dignified”.
“Today there’s been an overwhelming mood of dignity and respect and enjoyment and mutual co-operation,” he said.
“Most people are just here to enjoy themselves and treat each other with mutual respect.
Earlier on , thousands paraded through Sandy Row in south Belfast, many wearing traditional dress, reminiscent of 1912.
The leader of the Progressive Unionist Party, Billy Hutchinson, addressed the crowd. He told them to “march with pride, march with the wind of history at their back and the spirit of the Ulster Covenant at their core”.
Marchers had been arriving at Stormont on Saturday afternoon. Belfast-based marchers paraded back into the city at 16:15 BST; others returned home by bus.