On the 1st of January 1798, Colonel Cradock was advanced to the rank of major-general, and served as quartermaster-general in Ireland during the rebellion of that year; was under the command of Lieut.-General Gerard (afterwards Viscount) Lake at the affair with the rebels at Vinegar Hill, and in the subsequent movements in the county of Wexford. Major-General Cradock accompanied Earl Cornwallis as quartermaster-general in his lordship’s march against the French forces that landed in Killala under General Humbert, and was severely wounded in the action at Ballynahinch, when the French and rebel force were defeated, and laid down their arms.
Major-General Cradock was afterwards appointed to the staff of the Mediterranean, under General Sir Ralph Abercromby, and proceeded on the expedition to Egypt, and was in the actions of the 8th, 13th, and 21st of March 1801. In that of the 13th, near Alexandria, he commanded the brigades which formed the advance against the enemy, and received the thanks of Sir Ralph Abercromby. He was second in command of the division of the army that proceeded to Cairo under the command of Lieut.-General Hutchinson (afterwards the Earl of Donoughmore), and was at the action of Rhamanie on the 9th of May 1801, and at the surrender of Cairo and Alexandria. The surrender of the latter place on the 2d of September following, terminated the campaign, after which he was appointed to the command of a force of 4,000 men, to proceed to Corfu; but the preliminaries of peace being signed on the 1st of October between Great Britain and France, put an end to the expedition, and he returned to England, when he was again honored with the thanks of Parliament. The Grand Seignior had also established the order of knighthood of the Crescent, of which the general officers who served in Egypt were made members.
On the 8th of May 1801, Major-General Cradock had been appointed colonel commandant of the fifty-fourth regiment, and upon the reduction of the army, in 1802, he was placed on half-pay. On the 6th of August 1803, he was appointed colonel of the SEVENTY-FIRST regiment.
On the 1st of January 1805, Major-General Sir John Cradock, K.B., was advanced to the rank of lieut.-general, and appointed to the command of the forces at Madras. Upon the departure from India of General Lord Lake, in 1806, Lieut.-General Sir John Cradock remained for nearly a year in the command of the forces in that country. In 1808 he was appointed to command the forces in Portugal, during the critical period preceding the arrival of Lieut.-General Sir Arthur Wellesley, and was afterwards appointed Governor of Gibraltar, which in a short time he resigned. On the 6th of January 1809, he was removed from the SEVENTY-FIRST to the colonelcy of the forty-third regiment. In 1811 he was appointed governor of the Cape of Good Hope, and commander of the forces on that station, which he held until 1814, on the 4th of June of which year he was promoted to the rank of general.