Egerton continued with Hill for the rest of the Peninsular War, participating in the final engagement, the Battle of Toulouse, on 10 April 1814.

When the Hundred Days campaign began he returned to service, again as aide de camp to Hill, and fought at the Battle of Waterloo on 18 June 1815.

Egerton was subsequently promoted to brevet colonel on 10 January 1837 and in the 1838 Coronation Honours was appointed a Companion of the Order of the Bath.

[1] Egerton appears in the painting The Waterloo Banquet and was invited to that annual event celebrating the battle at Apsley House until at least 1852.

[7] He and his wife Arabella, the sister of fellow army officer Lieutenant-Colonel William Tomkinson,[8] lived with Hill in his final years, with Egerton acting as his private secretary and financial manager.

[4][5] Egerton later moved to Tarporley, renting Arderne Hall[9] and building an abbey folly on what is now part of Portal Golf Club.