The Prince of Orange, who had now been proclaimed King at Westminster, found that he must fight for his throne, and that Ireland was to be the battle-field. Londonderry was crowded with Protestants, who held out for William III. James believed that the place would fall without a blow. Count Rosen was of the same opinion. The Irish army proceeded northwards without resistance. The country, as far as the walls of Derry, was found abandoned by the population. Everything valuable had been destroyed by bands of Rapparees. There was great want of food for the army.

Nevertheless, James proceeded as far as Derry. Confident of success, he approached within a hundred yards of the southern gate, when he was received with a shout of "No surrender!" The cannon were fired from the nearest bastion. One of James's officers was killed by his side. Then he fled. A few days later he was on his way to Dublin, accompanied by Count Rosen.

Londonderry, after an heroic contest, was at length relieved. A fleet from England, laden with food, broke the boom which had been thrown by the Irish army across the entrance to the harbour. The ships reached the quay at ten o'clock at night. The whole population were there to receive them. The food was unloaded, and the famished people were at length fed. Three days after, the Irish army burnt their huts, and left the long-beleaguered city. They retreated along the left bunk of the Boyne to Strabane.

While the Irish forces were lying there, the news of another disaster reached them. The Duke of Berwick lay with a strong detachment of Irish troops before Enniskillen. He had already gained some advantage over the Protestant colonists, and the command reached him from Dublin that he was immediately to attack them. The Irish were five thousand in number; the Enniskilleners under three thousand.

An engagement took place at Newton Butler. The Enniskillen horse swept the Irish troops before them. Fifteen hundred were put to the sword, and four hundred prisoners were taken. Seven pieces of cannon, fourteen barrels of powder, and all the drums and colours were left in the hands of the victors. The Irish army were then at Strabane, on their retreat from Londonderry. They at once struck their tents, threw their military stores into the river, and set out in full retreat for the south.

In the meantime a French fleet had landed at Bantry Bay, with three thousand men on board, and a large convoy of ammunition and provisions. William III., on his part, determined, with the consent of the English Parliament, to send a force into Ireland to encounter the French and Irish forces under King James.

William's troops consisted of English, Scotch, Dutch, and Danes, with a large admixture of French Huguenots. There were a regiment of Huguenot horse, of eight companies, commanded by the Duke of Schomberg, and three regiments of Huguenot foot, commanded by La Mellonière, Du Cambon, and La Caillemotte. Schomberg, the old Huguenot chief, was put in command of the entire force.

Rapin accompanied the expedition as a cadet. The army assembled at Highlake, about sixteen miles from Chester. About ninety vessels of all sorts were assembled near the mouth of the Dee. Part of the army was embarked on the 12th of August, and set sail for Ireland. About ten thousand men, horse and foot, were landed at Bangor, near the southern entrance to Belfast Lough. Parties were sent out to scour the adjacent country, and to feel for the enemy. This done, the army set out for Belfast.

James's forces had abandoned the place, and retired to Carrickfergus, some ten miles from Belfast, on the north coast of the Lough. Carrickfergus was a fortified town. The castle occupies a strong position on a rock overlooking the Lough. The place formed a depôt for James's troops, and Schomberg therefore determined to besiege the fortress.

Rapin has written an account of William's campaigns in England and Ireland; but with becoming modesty he says nothing about his own achievements. We must therefore supply the deficiency. Before the siege of Carrickfergus, he had been appointed ensign in Lord Kingston's regiment. He was helped to this office by his uncle Daniel, who accompanied the expedition. Several regiments of Schomberg's army were detached from Belfast to Carrickfergus, to commence the siege. Among these was Lord Kingston's regiment.