The Relief of Londonderry: Breaking the boom

Forced to abdicate and flee England by the so-called 'Glorious Revolution' of 1688, the Catholic King James II initially escaped to France but went to Ireland the following year (1689), with armed support from Louis XIV, in a vain attempt to recover his throne. In the event, the campaign to reassert James's rule over Ireland faltered soon after the arrival of English troops but the threat of insurrection remained well into the next year, when William III decided to take personal control of his army across the Irish Sea. Once ashore, William rapidly consolidated his forces and decisively defeated James at the battle of the Boyne (12th July 1690) thereby ending Stuart pretensions and forcing James back into exile in France.

The year before the final victory at the Boyne however, in the spring of 1689, the Jacobite forces laid siege to the Protestant city of Londonderry which, after three months, was starving and close to surrender. General Piercy Kirke, in command of the relief force, sent two supply ships, Phoenix and Mountjoy, up the River Foyle escorted by the frigate Dartmouth. Successfully 'breaking the boom' with the aid of the ships' boats, the supply ships made it into the city and enabled the inhabitants to continue to hold out. Eventually, on 31st July [1689], the Jacobites withdrew and quit the field after an epic siege which had lasted for 111 days.