Why did Britain and France fight on the same side in 1718?
The War of the Quadruple Alliance remains a historical anomaly: a brief moment in the eighteenth century when Britain and France stood united. Driven by Spanish territorial ambitions and a web of dynastic conspiracies, this conflict spanned from the Mediterranean to the Americas, reshaping the map of Europe in its wake.
The conflict was triggered by Philip V of Spain, who sought to reclaim territories lost under the 1713 Peace of Utrecht. Encouraged by his wife, Elisabeth Farnese, and his Chief Minister, Cardinal Giulio Alberoni, Philip aimed to recover Sardinia and Sicily. These islands were vital to his dynastic goals, but his expansionist moves directly challenged the fragile European order established after the War of the Spanish Succession.
By 1717, Britain, France, and the Dutch Republic had formed the Triple Alliance to enforce the Utrecht terms, which strictly forbade the unification of the French and Spanish crowns. When Spain invaded Sardinia in 1717 and Sicily in 1718, the alliance expanded to include Austria, forming the Quadruple Alliance. The ensuing war saw the Royal Navy decisively destroy the Spanish fleet at the Battle of Cape Passaro in August 1718, effectively isolating Spanish forces on Sicily.
The war was fought on multiple fronts, including a failed Jacobite uprising in Scotland and colonial skirmishes in North America. Cardinal Alberoni’s attempt to destabilize the French regency through the Cellamare conspiracy backfired, leading to France’s formal entry into the war. By the time the Treaty of The Hague was signed in 1720, Spain was forced to relinquish its conquests. While Philip failed to regain his lost Mediterranean territories, the treaty secured his son’s future succession to the Duchy of Parma and Piacenza, marking the end of a rare period of Anglo-French cooperation.
Source: War of the Quadruple Alliance
