Prince Charles inspected serving soldiers and officers, as well as veterans, as they marched past him to the sound of the band of the Royal Regiment of Fusiliers.
Captain Mark Taylor from the Queen's Own Yeomanry said it was a "massive honour" to be inspected by His Royal Highness - who is the regiment's Royal Honorary Colonel.
The regiment's headquarters are at Fenham Barracks, Newcastle, but it has squadrons based in Northern Ireland and Scotland, as well as England.
The parade was the first time the whole regiment had exercised the freedom of the city of Newcastle - an honour which allows them to march with band playing and bayonets fixed.
Captain Taylor said they "could not have asked for anything more" than to have Prince Charles witnessing the parade.
Corporal Paul Codling, who has driven the regiment's armoured Scimitar tanks in Afghanistan, said he was more nervous driving past His Royal Highness.
"I was scared of breaking down," he told Sky News.
"That would have been a disaster."