After serving as a member of parliament for Carnarvon and then for Milborne Port, he took part in the Flanders Campaign and then commanded the cavalry for Sir John Moore's army in Spain during the Peninsular War; his cavalry showed distinct superiority over their French counterparts at the Battle of Sahagún and at the Battle of Benavente, where he defeated the elite chasseurs of the French Imperial Guard.

During the Hundred Days he led the charge of the heavy cavalry against Comte d'Erlon's column at the Battle of Waterloo.

[7] At the outbreak of the French Revolutionary Wars, Paget raised a regiment of Staffordshire volunteers and was given the temporary rank of lieutenant-colonel-commandant in December 1793.

[16] He inherited the title of Earl of Uxbridge on his father's death in March 1812 and was appointed a Knight Grand Cross of the Order of the Bath on 4 January 1815.

[16] A 27-metre (89 ft) high monument to his heroism (designed by Thomas Harrison) was erected at Llanfairpwllgwyngyll on Anglesey, close to Paget's country retreat at Plas Newydd, in 1816.

Still an impressive horseman even with a cork leg, George Whyte-Melville recalled the crowds that formed to cheer Paget as his well-ridden hack wended the London route from Piccadilly into Albemarle Street.

[34] Paget spent the following thirteen years out of office, then joined Lord John Russell's administration as Master-General of the Ordnance in July 1846.

[35] He was promoted to field-marshal on 9 November 1846[36] and, having been appointed Lord Lieutenant of Staffordshire on 31 January 1849,[37] he finally retired from the Government in March 1852.

[40] He died of a stroke at Uxbridge House in Burlington Gardens on 29 April 1854 and was buried at Lichfield Cathedral, where a monument is erected to his honour.

While his Lordship lived in the same house sat at the same table and frequented the same Company with his wife he treated her person with the coldest indifference and neglect withholding all Connubial intercourse with her and constantly sleeping in a different room from her.

In November 1808, Paget went to Spain to fight in the Peninsular War, but on his return he and Lady Charlotte resumed their affair, and in March 1809 they scandalously eloped and began living together.

On 28 March 1809, Lady Charlotte's brother, Henry Cadogan, challenged Paget to a duel: "My Lord, I hereby request you to name a time and place where I may meet you, to obtain satisfaction for the injury done myself and my whole family by your conduct to my sister.

"[45]The contest took place on Wimbledon Common on the morning of 30 May with Hussey Vivian as Lord Paget's second and Captain McKenzie as Cadogan's.

[43] The divorce was granted in Scotland, and Lord Paget and (the already pregnant) Lady Charlotte married in Edinburgh on 15 November 1810.