The significance of Waterloo

William Sadler, The Battle of Waterloo (1815)

On this day, the Battle of Waterloo was fought in 1815. It is often remembered as a dramatic military clash that ended Napoleon's final bid for power. But for Britain today, its relevance is not merely historical. The battle's aftermath shaped the modern British state, its economy, its place in the world, and even its national character. This is why I think Waterloo still matters.

Waterloo was the final act of the Napoleonic Wars, a generation of conflict that had consumed Europe. The decisive victory ensured Napoleon's defeat and exile, ending 25 years of near-continuous warfare between Britain and France. This ushered in a period known as the Pax Britannica: roughly a century in which Britain faced no existential military threat from a single European power. With Europe relatively stable, Britain could focus its energies elsewhere: expanding its empire, developing its industries, and building the Royal Navy that would police the world's oceans. The global order that emerged from the Congress of Vienna (1815), which attempted to create a balance of power among Europe's great nations, was directly linked to the defeat of Napoleon.

The decades after Waterloo saw Britain transform into the workshop of the world. Victory removed trade restrictions and continental blockades, opening European markets to British manufactured goods. The financial and industrial innovations that powered the Industrial Revolution accelerated. With its main rival defeated, Britain could also expand its colonial reach with fewer constraints. The British Empire grew to cover a quarter of the globe, and London became the centre of international finance. Without Waterloo, the trajectory of nineteenth-century globalisation, and Britain's central role in it, would have looked very different.

Winning the war came at a staggering cost. Britain's national debt had ballooned during the French wars. In response, the post-Waterloo government, led by Lord Liverpool, introduced a new fiscal framework. Income tax, introduced during the wars as a temporary measure, was repealed in 1816 but later permanently reintroduced in 1842 (Peel), and a sinking fund was established to manage debt. Perhaps more importantly, the stability that followed allowed for the slow, often painful, expansion of the electoral franchise, leading to the Great Reform Act of 1832. It also encouraged the reform of brutal criminal laws, overcrowded prisons, and inadequate poor relief. The modern British state, with its more accountable institutions and its cautious approach to constitutional change, emerged from this post-war settlement.

It can be argued that Waterloo entered British memory as the nation's greatest military victory before the world wars. The "Iron Duke", the Duke of Wellington, became a national hero, later serving as Prime Minister. The battle was commemorated in songs, poems (Byron's Childe Harold), and countless engravings. It reinforced a sense of British exceptionalism: the plucky island nation standing alone (with allies) against tyranny. While the First and Second World Wars have since overshadowed Waterloo in popular memory, its imagery:  the steadfast squares, the cavalry charges, Wellington's calm defiance, still echoes in British cultural references to courage, resilience, and the defence of liberty.

The Congress of Vienna created a system of regular meetings among the great powers to prevent future general wars. This "Concert of Europe" was an early experiment in international diplomacy and conflict prevention. While it did not prevent all wars, it established norms of consultation and balance that influenced later institutions, including the League of Nations and the United Nations. Britain's role in that system, as a power committed to European stability but not entangled in every continental quarrel, has shaped its foreign policy ever since.

The Battle of Waterloo is not merely a date in a textbook. It ended a generation of war, secured Britain's rise to global pre-eminence, shaped its economy and its political institutions, and contributed to a sense of national identity that still lingers. To understand modern Britain, with its fiscal conservatism, its ambivalent relationship with Europe, and its pride in its military past, we need to recognise the significance of Waterloo.