[1] He subsequently served as an ADC to his father during campaigns in Flanders (1793–1794), the West Indies (1796–1797), Ireland (1798) and against the Batavian Republic (1799).

His father died in battle at Alexandria; but John continued to render admirable service, for which General Hutchinson commended him.

[1] When war broke out anew in 1803 the French detained Abercromby whilst he was travelling in France and imprisoned him at Verdun for the next five years.

The Indian climate had broken his health, however, and he had to return to Britain at the end of 1813, where he was appointed Knight Commander of the Order of the Bath.

[1] He was elevated to Knight Grand Cross of the Order of the Bath in 1815, and succeeded his elder brother George as Member of Parliament (MP) for Clackmannanshire.