A line of defenders, clad in red uniforms and armed with muskets and cannon, stand at one end of Derry’s Craigavon Bridge on Saturday.
They are there, the narrator explains, because of the actions of 13 apprentice boys who, in 1688, had the foresight to close the city’s gates against the approaching army of “the usurper” Catholic King James.
His name is booed loudly by the watching crowd; their cheers are for the “gallant William, Prince of Orange”. For 105 days, the course of European history hung on events in Derry.
The starving city managed to hold out until a relief ship got through. James lifted the siege and fled south, where he was defeated by William at the Battle of the Boyne.
Every year since 1690, members of the Apprentice Boys of Derry have paraded through the streets of the city to commemorate the Relief of the City.
Banners
Some 7,000 Apprentice boys and 150 bands follow banners decorated with images from the siege as they make their way through the walled city, watched by thousands crammed on to its narrow pavements.
“It’s part of my blood,” said Apprentice Boy Stephen McElwee, who played a musketeer in the pageant.
“It makes you realise what people went through in the past and what the siege was all about.”
Yet, more than 300 years on, the border city of Derry finds itself once again on the front line of European events, as uncertainty continues over the potential impact of Brexit.
Apprentice Boy and theatre producer Jonathan Burgess, who designed the pageant, describes himself as one of "few remainers" among those watching.
“The siege of Derry fundamentally meant that the parliament in London and the throne of England were maintained.
“I think there are long-term ramifications for the union on the basis of Brexit.
“In the long term, you’ll have your hard border certainty, but your hard border will be at airports and the Port of Belfast, so Northern Ireland will be cut off from the rest of the UK.
‘Soft road’
“In my opinion, it’s a soft road to a united Ireland . . . That’s not an aspiration of mine but it’s just a reality. If you’d said to me two years ago will I ever see a united Ireland I would have said under no circumstances, but post-Brexit I’m thinking it could come in my generation, and then what choices am I left to make?
“I’m a British citizen, I’m imbued with British culture, and if I’m not removing myself from my country but my country is removing itself from me, what does that do? That has sort of cast me astray.”
Davy Stewart from the Fivemiletown branch comes to the parade every year with his six-year-old son Jesse.
Originally from Monaghan but now living in Loughgall, Co Armagh, he voted to leave the EU. “It’s important to remember the past and what that victory meant for the UK and Europe and for the freedom and democracy we have today.
“I’m not totally against the EU, but I think it went too far. We didn’t have enough say in what was happening and it was taking away our sovereignty.
“As long as the border issue is sorted out I’m optimistic, and I think they’ll find a solution to that. Finding a solution to the problems of Northern Ireland is a bigger problem,” he said.