In conjunction with Turenne, Lockhart had been pushing on the war, and at length (May 1658) the two armies, and Montagu's fleet, were engaged in the exact service which Cromwell most desired, and Lockhart had been always urging.

This was the siege of Dunkirk, with a view to the possession of that town, as well as Mardike, by the English.

To be near the scene of such important operations, Louis XIV.

and Cardinal Mazarin had taken up their quarters at Calais; and, not to miss the opportunity of such near approach of the French monarch to the shores of England, Cromwell despatched his son-in-law Viscount Falconbridge on a splendid embassy of compliment and congratulation.

He landed at Calais on the 29th of May, was received by both King and Cardinal with such honours as they had never accorded to an ambassador before, and returned on the 3rd of June to make his report.