A second battalion was raised in 1804 to increase the strength of the regiment.
The 1st battalion embarked for Copenhagen in July 1807 and saw action at the Battle of Copenhagen in August 1807 during the Gunboat War before returning home in November 1807.
It then embarked for Portugal in May 1808 for service under General Sir Arthur Wellesley in the Peninsular War and saw action at the Battle of Roliça in August 1808 and the Battle of Vimeiro later that month.
In January 1809 the battalion took part in the Battle of Corunna, commanded by Charles James Napier carrying out successive bayonet charges to keep the French at bay to which General Sir John Moore shouted "Well done, 50th!
Well done, my Majors!".
The battalion was subsequently evacuated from the Peninsula.
Both battalions then embarked from the Downs in July 1809 and saw action in the disastrous Walcheren Campaign.
It was the last regiment to leave Holland in December 1809.

The 1st battalion returned to Portugal in September 1810 and took part in the Battle of Fuentes de Oñoro in May 1811, the Battle of Arroyo dos Molinos in October 1811 and the Battle of Almaraz in May 1812 as well as the Battle of Vitoria in June 1813.
It then pursued the French Army into France and fought at the Battle of the Pyrenees in July 1813, the Battle of Nivelle in November 1813 and the Battle of the Nive in December 1813 as well as the Battle of Orthez in February 1814 and the Battle of Toulouse in April 1814.
The regiment returned to Ireland in July 1814.
A second battalion was raised in 1804 to increase the strength of the regiment. The 1st battalion embarked for Copenhagen in July 1807 and saw action at the Battle of Copenhagen in August 1807 during the Gunboat War before returning home in November 1807. It then embarked for Portugal in May 1808 for service under General Sir Arthur Wellesley in the Peninsular War and saw action at the Battle of Roliça in August 1808 and the Battle of Vimeiro later that month. In January 1809 the battalion took part in the Battle of Corunna, commanded by Charles James Napier carrying out successive bayonet charges to keep the French at bay to which General Sir John Moore shouted "Well done, 50th! Well done, my Majors!". The battalion was subsequently evacuated from the Peninsula. Both battalions then embarked from the Downs in July 1809 and saw action in the disastrous Walcheren Campaign. It was the last regiment to leave Holland in December 1809.
The 1st battalion returned to Portugal in September 1810 and took part in the Battle of Fuentes de Oñoro in May 1811, the Battle of Arroyo dos Molinos in October 1811 and the Battle of Almaraz in May 1812 as well as the Battle of Vitoria in June 1813. It then pursued the French Army into France and fought at the Battle of the Pyrenees in July 1813, the Battle of Nivelle in November 1813 and the Battle of the Nive in December 1813 as well as the Battle of Orthez in February 1814 and the Battle of Toulouse in April 1814. The regiment returned to Ireland in July 1814.
50th (Queen's Own) Regiment of Foot