HistoryData
Historical ConflictDerry

Siege of Derry

The 105-day Jacobite siege of Derry in 1689 was the opening major engagement of the Williamite War in Ireland, ending in a Protestant defensive victory.

Duration & Scope

1689 ongoing

< 1 year

Key Facts

Duration
105 days (18 April – 1 August 1689)
First attempted breach
7 December 1688, repelled by 13 apprentices
Jacobite commander
King James II appeared personally before the walls
Siege broken by
Supply ships breaking through the boom
Annual commemoration
Observed yearly by the Protestant community

Strategic Narrative Overview

The formal siege began on 18 April 1689 when James II himself led an Irish army, stiffened by Jacobite and French officers, to the walls and demanded surrender. The garrison refused. Jacobite attempts to storm the walls failed, leading the besiegers to adopt a strategy of starvation. A boom was stretched across the River Foyle to cut off resupply. The town endured severe privation over 105 days while holding out.

01 / The Origins

Following the Glorious Revolution in England, Ireland became a theatre of conflict between the deposed Catholic King James II and the Protestant William of Orange. Derry, a Protestant-held town, became a flashpoint when Jacobite forces attempted to garrison it in December 1688. Thirteen apprentices famously shut the gates against the Jacobite troops, an act of defiance that set the stage for the full siege months later.

03 / The Outcome

The siege ended on 1 August 1689 when relief ships broke through the boom on the River Foyle, resupplying the starving garrison. Jacobite forces abandoned the siege and withdrew. The successful defence boosted the Williamite cause in Ireland and denied James II control of a strategically important northern stronghold early in the campaign. The event became a defining symbol for Ulster Protestant identity.

Belligerents & Mobilization Analysis

Side A

1 belligerent

Jacobite forces (Irish and French)
Key Commanders

James II.

Side B

1 belligerent

Williamite garrison of Derry
Outcome
Williamite/defender victory; Jacobite forces lifted the siege after relief ships broke through on 1 August 1689

Kinetic Engagement Axis

Major engagements timeline (1689–present)Timeline of major military engagements plotted chronologically.1689present1688First Jacobite a…Side B1689Siege of DerrySide B

Scroll horizontally to view full axis. Events plotted relatively.

Side A victorySide B victoryInconclusiveDecisive / turning point

Location

Map of Derry, IrelandMap of Derry, IrelandDerry, Ireland