Around 2,500 people took part in a parade and ceremony on Saturday evening to commemorate the 36th Ulster Division and their role in the Battle of the Somme.
A new inscription on the memorial obelisk in the town centre plaza was unveiled by MLA Captain Doug Beattie.
Prior to the official dedication, those taking part had paraded from Carrickblacker to Edgarstown, where the 36th Ulster Division Memorial Arch had been erected for the occasion and past the new commemorative mural at Union Street.
A spokesperson for The Unionist Centenary Committee Portadown said, “The committee would like to thank all participants, bands and organisations who took part in the parade, the members of the public who lined the route, the Rev Ken Robinson, the Rev Bill Adair, the local councillors and the MLAs in attendance at the dedication of the memorial obelisk.
“The ceremony of dedication was conducted in a dignified and solemn manner befitting the memory of the 36th Ulster Division.
“We are indebted to the local community for once again displaying their full support in this latest of centenary events.”
He added, “The new inscription to the obelisk, whilst insignificant in comparison, is a permanent reminder to the people of Portadown of the sacrifice paid in battle by so many of the 36th Ulster Division.”
Bands taking part were Pride of the Raven Flute Band, Portadown Defenders Flute Band, Portadown True Blues Flute Band, Cookstown Sons of William Flute band and Portadown Defenders Auld Boys.
The inscription uses the words of Capt Wilfred Spender, reported in the press on July 2, 1916.
Part of it reads, “I am not an Ulsterman but yesterday, the 1st July, as I followed their amazing attack, I felt that I would rather be an Ulsterman than anything else in the world. The Ulster Division has lost more than half the men who attacked and, in doing so, has sacrificed itself for the Empire...”