Sir John Fenwick, adhering to the interest of King James, resigned his commission; and the Colonelcy of the regiment was given to Lord Colchester, from the Lieutenant-Colonelcy of the Fourth Troop of Life Guards, who was one of the first officers that joined the Prince of Orange at Exeter, and took with him several men of his troop. [Sidenote: 1689] After the flight of the King, the Roman Catholic soldiers committed some irregularities; and in January, 1689, a squadron of the FOURTH HORSE, with a detachment of Sir George Hewyt's Horse (now Sixth Dragoon Guards), marched to Lewes and Chichester, where they caused three regiments of Irish Roman Catholics[12] to lay down their arms, and afterwards escorted them to Portsmouth; from whence they were removed, under a strong guard, to the Isle of Wight, and were subsequently, sent to Hamburg, and disposed of in the service of the Emperor of Germany. In the mean time the accession of King William and Queen Mary to the throne was opposed in Scotland, and Viscount Dundee was actively engaged in exciting the northern shires, particularly the Highlanders, to take arms in favour of King James. The FOURTH HORSE, after transferring thirty men and horses to the Blues (which regiment was ordered to proceed to Holland), marched for Scotland, and were placed under the command of Major-General Mackay. Having arrived at Edinburgh early in April, the FOURTH HORSE formed part of the force employed in the siege of the castle, which the Duke of Gordon held possession of for King James. Shortly afterwards one squadron of the regiment, with two squadrons of the Royal Scots Dragoons (the Greys), and two hundred foot, accompanied Major-General Mackay to the town of Dundee, where two troops of the Royal Scots Dragoons were left, and the remainder proceeded in quest of the rebels. Major-General Mackay having ascertained that Viscount Dundee had joined Macdonald of Keppoch, who lay before Inverness with a thousand men, determined to confront them with his little band. He crossed the Spey, and advanced to Elgin with all possible speed, and throughout the march he was rejoiced (as he observes in his memoirs) to find his troops animated with the same spirit as himself. At Elgin the squadron of the FOURTH HORSE halted two days in quarters of refreshment, the men and horses being nearly exhausted. On the third day they proceeded towards Forres, and on the march the General ascertained that Viscount Dundee had taken the road through Badenoch to Lochaber. The squadron then proceeded to Inverness, where Major-General Mackay invited the influential persons in the neighbourhood to meet him to concert measures for opposing the rebels; and, expecting that Viscount Dundee would soon appear with a vast accession of force, several additional corps were ordered from Edinburgh to Inverness. At the same time the remainder of the FOURTH HORSE were also directed to proceed to the same destination.