John Churchill, 1st Duke of Marlborough, defeats a French army under Marshal François de Neufville, duc de Villeroy in the Battle of Ramillies.

The Battle of Ramillies (), fought on 23 May 1706, was a battle of the War of the Spanish Succession. For the Grand Alliance Austria, England, and the Dutch Republic the battle had followed an indecisive campaign against the Bourbon armies of King Louis XIV of France in 1705. Although the Allies had captured Barcelona that year, they had been forced to abandon their campaign on the Moselle, had stalled in the Spanish Netherlands and suffered defeat in northern Italy. Yet despite his opponents' setbacks Louis XIV wanted peace, but on reasonable terms. Because of this, as well as to maintain their momentum, the French and their allies took the offensive in 1706.

The campaign began well for Louis XIV's generals: in Italy Marshal Vendme defeated the Austrians at the Battle of Calcinato in April, while in Alsace Marshal Villars forced the Margrave of Baden back across the Rhine. Encouraged by these early gains Louis XIV urged Marshal Villeroi to go over to the offensive in the Spanish Netherlands and, with victory, gain a 'fair' peace. Accordingly, the French Marshal set off from Leuven (Louvain) at the head of 60,000 men and marched towards Tienen (Tirlemont), as if to threaten Zoutleeuw (Lau). Also determined to fight a major engagement, the Duke of Marlborough, commander-in-chief of Anglo-Dutch forces, assembled his army some 62,000 men near Maastricht, and marched past Zoutleeuw. With both sides seeking battle, they soon encountered each other on the dry ground between the rivers Mehaigne and Petite Gette, close to the small village of Ramillies.

In less than four hours Marlborough's Dutch, English, and Danish forces overwhelmed Villeroi's and Max Emanuel's Franco-Spanish-Bavarian army. The Duke's subtle moves and changes in emphasis during the battle something his opponents failed to realise until it was too late caught the French in a tactical vice. With their foe broken and routed, the Allies were able to fully exploit their victory. Town after town fell, including Brussels, Bruges and Antwerp; by the end of the campaign Villeroi's army had been driven from most of the Spanish Netherlands. With Prince Eugene's subsequent success at the Battle of Turin in northern Italy, the Allies had imposed the greatest loss of territory and resources that Louis XIV would suffer during the war. Thus, the year 1706 proved, for the Allies, to be an annus mirabilis.

General John Churchill, 1st Duke of Marlborough, 1st Prince of Mindelheim, 1st Count of Nellenburg, Prince of the Holy Roman Empire, (26 May 1650 – 16 June 1722 O.S.) was an English soldier and statesman whose career spanned the reigns of five monarchs. From a gentry family, he served first as a page at the court of the House of Stuart under James, Duke of York, through the 1670s and early 1680s, earning military and political advancement through his courage and diplomatic skill.

Churchill's role in defeating the Monmouth Rebellion in 1685 helped secure James on the throne, but he was a key player in the military conspiracy that led to James being deposed during the Glorious Revolution. Rewarded by William III with the title Earl of Marlborough, persistent charges of Jacobitism led to his fall from office and temporary imprisonment in the Tower of London. William recognised his abilities by appointing him as his deputy in Southern Netherlands (modern-day Belgium) before the War of the Spanish Succession in 1701, but not until the accession of Queen Anne in 1702 did he secure his fame and fortune.

Marriage to Sarah Jennings and her relationship with Anne ensured Marlborough's rise, first to the captain-generalcy of British forces, then to a dukedom. As de facto leader of Allied forces in the Low Countries, his victories at Blenheim (1704), Ramillies (1706), Oudenarde (1708), and Malplaquet (1709) ensured his place in history as one of Europe's great generals.

His wife's stormy relationship with the Queen, and her subsequent dismissal from court, was central to his own fall. Incurring Anne's disfavour, and caught between Tory and Whig factions, Marlborough was forced from office and went into self-imposed exile. He returned to favour with the accession of George I to the British throne in 1714, but a stroke in 1716 ended his active career.

Marlborough's leadership of the Allied armies fighting Louis XIV from 1701 to 1710 consolidated Britain's emergence as a front-rank power, while his ability to maintain unity in the fractious coalition demonstrated his diplomatic skills. He is often remembered by military historians as much for his organisational and logistic skills as his tactical abilities. However, he was also instrumental in moving away from the siege warfare that dominated the Nine Years' War, arguing one battle was worth ten sieges.