Ensign Robert Lewis purchased a commission into the 45th  (Nottinghamshire) Regiment of Foot on the 7th of April 1825. He would serve with the Regiment during the 1st Burma War. 

In 1824, war was declared against Burma, on the 5th of March, after (in the words of Wylly from the regimental history (Colonel Wylly, History of the 1st and 2nd Battalions The Sherwood Foresters Nottinghamshire and Derbyshire Regiment (1740-1914), (1929))); “a Burmese general invaded [India] between Burma and Bengal, conquered Assam and Manipore, threatened Cachar, and, invading British territory, actually captured a party of Indian sepoys. The Burmese general then began to levy taxes on British boats trading on the river forming the boundary between Arakan and Chittagong, and finally, landing an armed party on the island at the mouth of the river, killed and wounded six of the British garrison.”  

The 45th were ordered to embark towards Burma in 1825, due to the large number of soldiers suffering from illness in the region. This was, however, called off due to the sheer numbers suffering from Cholera in the hot season in March. The regiment set out yet again and reached the scene of the hostilities, having traversed through jungle, shortly before peace was agreed at Vandabo, in February 1826. The regiment were subsequently awarded the battle honour ‘Ava’, for their part. 

After the war, Robert transferred regiments, becoming a Lieutenant in the 89th (Princess Victorias) Regiment of Foot, on the 2nd of March 1826. He would steadily rise through the ranks throughout his service with the 89th Foot. He became a Captain on the 12th of February 1828, then a Brevet Major (24th of November 1841) and then a Major (16th of April 1843). 

He became unattached on the 11th of November 1851 and was placed on half pay the following month. Robert would subsequently become a Colonel on the 28th of November 1854 and finally, a Major General on the 21st of January 1866. 

Robert sadly died, at Beulah Hill, Norwood, on the 22nd of July 1870.