[2] Smyth was commissioned as a cornet into the on 5 July 1821 and, promoted to Lieutenant on 26 May 1825, he fought at the Capture of Bharatpur later that year.

After 10 years with the 32nd he moved to the 6th Dragoon Guards, before being given a year-long leave of absence in 1830 to serve a prison sentence.

Frederick Markham, were imprisoned for manslaughter in the death of Standish Stanley O'Grady on 18 March 1830 in Ireland.

[3] Promoted to Major on 17 August 1841, he returned to the 16th Lancers on 6 May 1842 and served with it during the Gwalior campaign and First Anglo-Sikh War.

At the Battle of Aliwal, Smyth led the 16th Lancers to rout the Sikh cavalry and break a square of infantry; he was mentioned in dispatches and made a brevet Lieutenant-Colonel.