100th Regimental Colour as painted in 1820            

The 100th (County of Dublin) Regiment of Foot was raised in Ireland for service during the Napoleonic Wars. It arrived in North America in late 1805 and during the next 13 years spent its time in garrison posts from what we know today as the Maritimes to the western end of Ontario.

On May 4th, 1812, the War Office approved that the regiment's name would in future be styled "The 100th (or His Royal Highness the Prince Regent's County of Dublin) Regiment."

During the War of 1812, the 100th Regiment played a critical role in defending Canada participating in actions in both Upper & Lower Canada, and the United States. Several companies also acted as marines aboard ships on the Great Lakes.

Some of the regiment’s actions include:

- Battle of Sackets Harbor (May 1813)

- Capture of vessels Growler & Eagle (June 1813)

- Murray’s Raid (July to Aug 1813)

- Capture of Fort Niagara (Dec 1813)

- Raids on Buffalo & Black Rock (Dec 1813)

- Battle of Chippawa (July 1814)

- Siege of Fort Erie (Aug to Sept 1814)

- Skirmish at Cook’s Mills (Oct 1814)

On May 27th, 1815 the regiment was awarded the battle honour of 'Niagara' for their distinguished conduct in the capture of Fort Niagara by assault on the night of 19th December 1813.

On February 23rd, 1816, the War Office gave notice that the 95th Regiment would in future be styled the Rifle Brigade and taken out of the numbered Regiments of the Line. All following regiments had their unit number altered with the 100th Regiment to be renumbered the 99th retaining the title of H.R.H the Prince Regent's County of Dublin Regiment.

The 99th (late 100th) Regiment was disbanded in 1818 and members were offered a choice between land in Canada or transport back to England with many accepting grants of land. The largest concentration of the regiment's discharged soldiers was in the military settlement of Richmond. The village of Richmond is now part of the City of Ottawa.