Whilst the British sieges of the Peninsular War (1808–14) have long been studied from an operational point of view, it is only in very recent years that historians have turned their attention to examining what occurred to garrisons and civilians in the aftermath of the British storms of Ciudad Rodrigo, Badajoz and San Sebastian. This traditional neglect of the infamous British sacks of the Peninsular War is part of a broader neglect of the history of sieges in the Revolutionary-Napoleonic era, and of the laws of war in which they were conducted. Yet sieges played a crucial role in shaping the development of customary laws of war in early modern Europe. Moreover, whilst battles had well and truly supplanted sieges as the principal form of operational warfare by the time of the Napoleonic Wars, sieges nevertheless remained important to military and civilian experiences of war, not only within European theatres of war, but within the European colonial sphere.

This chapter explores the often forgotten 1807 British siege and capture of Montevideo during the ill-fated River Plate campaign of 1806–07. Whilst the siege operation has been covered in detail in a number of recent campaign histories, this chapter examines the siege through the prism of laws of war, with a particular focus on the British storming of the town and the subsequent fate of the garrison and civilians. The siege did not constitute a large-scale operation relative to many other contemporary sieges, but it is nevertheless of particular interest in terms of the evolution of customary laws of war, and of how soldiers interpreted and enforced those laws, especially when compared with the more famous British sieges of the Peninsular War. In Spain, after storming the towns of Ciudad Rodrigo, Badajoz and San Sebastian, British troops spared the French garrisons but notoriously sacked the towns and committed atrocities against the Spanish inhabitants. Yet at Montevideo the opposite was true: a rare example of a besieged city taken by storm, where the enemy was initially given no quarter, but the inhabitants were spared the fate of sack.

The Siege and Its Context

The siege of Montevideo took place within the extraordinary context of the British invasion of the River Plate in 1806–07. Here, unlike what would soon unfold in the Peninsular War, British forces faced Spain as a traditional imperial rival and enemy.