High treason The nadir of Marlborough's fortunes had not yet been reached. The spring of 1692 brought renewed threats of a French invasion and new accusations of Jacobite treachery. Acting on the testimony of Robert Young, the Queen had arrested all the signatories to a letter supporting the restoration of James II and the seizure of King William. Marlborough, as one of these signatories was sent to the Tower of London on 4 May (O.S) where he languished for five weeks; his anguish compounded by the news of the death of his younger son Charles on 22 May (O.S). Young's letters were eventually discredited as forgeries and Marlborough released, but he continued his correspondence with James, leading to the celebrated incident of the "Camaret Bay letter" of 1694.<58>

For several months the Allies had been planning an attack against Brest, the French port in the Bay of Biscay. The French had received intelligence alerting them to the imminent assault, enabling Marshal Vauban to strengthen its defences and reinforce the garrison. Inevitably, the attack on 18 June, led by the English General Thomas Tollemache, ended in disaster; most of his men were killed or captured – Tollemache himself died of his wounds shortly afterwards.<59> Despite lacking evidence, Marlborough's detractors claimed that it was he who had alerted the enemy.<58><60> But although it is practically certain that Marlborough sent a message across the Channel in early May describing the impending attack on Brest, it is equally certain that the French had long learned of the expedition from another source – possibly Godolphin or the Earl of Danby.<58> Winston Churchill goes as far as to say that the letter was a forgery, but David Chandler states – "the whole episode is so obscure and inconclusive that it is still not possible to make a definite ruling. In sum, perhaps we should award Marlborough the benefit of the doubt."<61>

Reconciliation Mary's death on 28 December 1694 (O.S), eventually led to a formal, but cool, reconciliation between William and Anne, now heir to the throne. Marlborough hoped that the rapprochement would lead to his own return to office, but although he and Lady Marlborough were allowed to return to court, the earl received no offer of employment.<61> In 1696 Marlborough, together with Godolphin, Russell and Shrewsbury, was yet again implicated in a treasonous plot with King James, this time instigated by the Jacobite militant Sir John Fenwick. The conspiracy was eventually dismissed as a fabrication and Fenwick executed – the King himself had remained incredulous of the accusations – but it was not until 1698, a year after the Treaty of Ryswick brought an end to the Nine Years War, that the corner was finally turned in William's and Marlborough's relationship.<61> On the recommendation of Lord Sunderland (whose wife was also a close friend of Lady Marlborough), William eventually offered Marlborough the post of governor to the Duke of Gloucester, Anne's eldest son. He was also restored to the Privy Council, together with his military rank,<62> but striving to reconcile his close Tory connections with that of the dutiful royal servant was difficult, leading Marlborough to bemoan – "The King's coldness to me still continues."<63>

Queen Mary II died childless in 1694 (O.S), leaving her sister Anne as heir apparent.

Later life (1700–22) War of the Spanish Succession Main article: War of the Spanish Succession With the death of the infirm and childless King Charles II of Spain on 1 November 1700, the succession of the Spanish throne, and subsequent control over her empire (including the Spanish Netherlands), once again embroiled Europe in war – the War of the Spanish Succession. On his deathbed, Charles had bequeathed his domains to King Louis XIV's grandson, Philip, Duc d'Anjou. This threatened to unite the Spanish and French kingdoms under the House of Bourbon – something unacceptable to England, the Dutch Republic, and the Austrian Emperor, Leopold I, who had himself a claim to the Spanish throne. With William's health deteriorating (the King himself estimating he had but a short time to live), and with the Earl's undoubted influence over his successor Princess Anne, William decided that Marlborough should take centre stage in European affairs. Representing William in The Hague as Ambassador-Extraordinary, and as commander of English forces, Marlborough was tasked to negotiate a new coalition to oppose France and Spain. On 7 September 1701, the Treaty of the Second Grand Alliance was duly signed by England, the Emperor, and the Dutch Republic to thwart the ambitions of Louis XIV and stem Bourbon power.<64> William, however, was not to see England's declaration of war. On 8 March 1702 (O.S), the King, already in a poor state of health, died from injuries sustained in a riding accident, leaving his sister-in-law, Anne, to be immediately proclaimed as his successor. But although the King's death occasioned instant disarray amongst the coalition, Count Wratislaw was able to report – "The greatest consolation in this confusion is that Marlborough is fully informed of the whole position and by reason of his credit with the Queen can do everything."<65>

John Churchill, 1st Duke of Marlborough by Sir Godfrey Kneller. Pictured here in his garter robes.

This 'credit with the Queen' also proved personally profitable to her long-standing friends. Anxious to reward Marlborough for his diplomatic and martial skills in Ireland and on the continent, Marlborough became the Master-General of the Ordnance – an office he had long desired – made a Knight of the Garter and Captain-General of her armies at home and abroad. With Lady Marlborough's advancements as Groom of the Stole, Mistress of the Robes, and Keeper of the Privy Purse, the Marlboroughs, now at the height of their powers with the Queen, enjoyed a joint annual income of over £60,000, and unrivalled influence at court.<66>

Early campaigns On 4 May 1702 (O.S) England formally declared war on France. Marlborough was given command of the British, Dutch, and hired German forces, but the command had its limitations: as Captain-General he had the power to give orders to Dutch generals only when Dutch troops were in action with his own; at all other times he had to rely on the consent of accompanying Dutch field deputies or political representatives of the States-General – his ability to direct allied strategy would rely on his tact and powers of persuasion.<67> But despite being frustrated by his Dutch Allies' initial lassitude to bring the French to battle, the war began well for Marlborough who managed to out-manoeuvre the French commander, Marshal Boufflers.<68> In 1702 he had captured Venlo, Roermond, Stevensweert and Liège in the Spanish Netherlands for which, in December, a grateful Queen publicly proclaimed Marlborough a Duke and Marquess of Blandford.<69>

On 9 February 1703 (O.S), soon after the Marlboroughs' elevation, their daughter Elizabeth married Scroop Egerton, Earl of Bridgewater; this was followed in the summer by an engagement between Mary and John Montagu, heir to the Earl of, and later Duke of, Montagu, (they later married on 20 March 1705). Their two older daughters were already married: Henrietta to Godolphin's son Francis in April 1698, and Anne to the hot-headed and intemperate Charles Spencer, Earl of Sunderland in 1700.<70> However, Marlborough's hopes of founding a great dynasty of his own reposed in his eldest and only surviving son, John, who, since his father's elevation had borne the courtesy title of Marquess of Blandford. But while studying at Cambridge in early 1703, the 17 year-old was stricken with a severe strain of smallpox. His parents rushed to be by his side, but on Saturday morning, 20 February the boy died, plunging the duke into 'the greatest sorrow in the world'; he later lamented to Lord Ailesbury – "I have lost what is so dear to me."<71>

Bearing his grief, and leaving Sarah to hers, the Duke returned to The Hague at the beginning of March. By now Marshal Villeroi had replaced Boufflers as commander in the Spanish Netherlands,<72> but although Marlborough was able to take Bonn, Huy, and Limbourg in 1703, continuing Dutch hesitancy prevented him from bringing the French in Flanders to a decisive battle.<73> Domestically the Duke also encountered resistance. Both he and Godolphin were hampered by, and often at variance with, their High Tory colleagues who, rather than advocating a European policy, favoured the full employment of the Royal Navy in pursuit of trade advantages and colonial expansion overseas. For their part, the Whigs, although enthusiastic for the European strategy, had dropped all pretence at supporting the conduct of the war, accounting Marlborough and Godolphin guilty of failing to provide gains commensurate with the funds generously granted them in Parliament.<74> The moderate Tory ministry of Marlborough and Godolphin found itself caught between the political extremes. However, Marlborough, whose diplomatic tact had held together a very discordant Grand Alliance, was now a general of international repute and the limited success of 1703 was soon eclipsed by the Blenheim campaign of 1704.<75>

Blenheim and Ramillies Pressed by the French and Bavarians to the west and Hungarian rebels to the east, Austria faced the real possibility of being forced out of the war. Concerns over Vienna and the need to ensure the continuing involvement of Emperor Leopold I in the Grand Alliance, had convinced Marlborough of the necessity of sending aid to the Danube; but the scheme of seizing the initiative from the enemy was extremely bold. From the start the Duke resolved to mislead the Dutch who would never willingly permit any major weakening of the allied forces in the Spanish Netherlands. To this end, Marlborough moved his English troops to the Moselle, (a plan approved of by The Hague), but once there, he resolved to slip the Dutch leash and march south to link up with Austrian forces in southern Germany.<77>

Marlborough writing the Blenheim despatch to Sarah, by Robert Alexander Hillingford. "I have no time to say more but to beg you will give my duty to the Queen, and let her know her army has had a glorious victory."<76>

A combination of strategic deception and brilliant administration enabled Marlborough to achieve his purpose.<78> After covering approximately 250 miles (400 km) in five weeks, Marlborough – together with Prince Eugene of Savoy – delivered a crushing defeat of the Franco-Bavarian forces at the Battle of Blenheim on 13 August 1704. The whole campaign, which historian John Lynn describes as one of the greatest examples of marching and fighting before Napoleon, had been a model of planning, logistics, and tactical skill, the successful outcome of which had altered the course of the conflict – Bavaria and Cologne were knocked out of the war, and Louis' hopes of an early victory were destroyed.<79> The campaign continued with the capture of Landau on the Rhine, followed by Trier and Trarbach on the Moselle. With these successes, Marlborough now stood as the foremost soldier of the age; even the Tories, who had declared that should he fail they would "break him up like hounds on a hare", could not entirely restrain their patriotic admiration.<80>

The Queen lavished upon her favourite the royal manor of Woodstock and the promise of a fine palace commemorative of his great victory, but since her accession, her relationship with Sarah had become progressively distant.<81> The Duke and Duchess had risen to greatness not least because of their intimacy with Anne, but Sarah had tired of petty ceremony and formality of court life and increasingly found her mistress's company wearisome. For her part, Anne, now Queen of England and no longer the timid adolescent so easily dominated by her more beautiful friend, had grown tired of Sarah's tactless political hectoring and increasingly haughty manner.<82> Queen Anne enthusiastically agreed to Emperor Leopold’s offer (made during the duke’s march to the Danube) to make Marlborough a prince of the Holy Roman Empire in the small principality of Mindelheim – the Bavarian estate which had been confiscated from the Elector and effectively occupied after Blenheim.<83> But after the successes of 1704, the campaign of 1705 brought little reason for satisfaction on the continent. Endless delays and evasions from his Allies had once again frustrated Marlborough's attempts at any major offensive.<84> "I find so little zeal for the common cause that it is enough to break a better heart than mine," he confided to Anthonie Heinsius.<85> Although Marlborough had been able to penetrate the Lines of Brabant in July, allied indecision had prevented the Duke from pressing his advantage.<86

The year 1705 had provided the French time to reorganize their forces. Marshal Villars’ successes against Baden along the Rhine, and Vendome’s victory at Calcinato in Italy, had thwarted Marlborough's original plan for 1706 – a possible march to Italy to link up with Prince Eugene.<87> The Duke, however, soon adjusted his schemes. In May Marlborough marched into enemy territory, hoping to lure Marshal Villeroi into accepting battle. Equally determined to fight, and keen to avenge Blenheim, King Louis goaded his commander to seek out 'Monsieur Marlbrouck'. The subsequent Battle of Ramillies, fought in the Spanish Netherlands on 23 May 1706, was perhaps Marlborough's most successful action, one which, in the words of Villars, had caused "the most shameful, humiliating and disastrous of routs" of French forces. For the loss of less than 3,000 dead and wounded (far fewer than Blenheim), his victory had inflicted over 20,000 casualties on the enemy. Town after town fell, but although the campaign was not decisive, it was an unsurpassed operational triumph for the English general.<88> When Marlborough eventually closed down the Ramillies campaign, he had completed the conquest of almost all the Spanish Netherlands. Good news for the Allies also arrived from the Italian front – in September Prince Eugene routed the French army at Turin. After his victory at Ramillies the titular 'Charles III' offered Marlborough the governorship of the Spanish Netherlands, worth £60,000 per annum. But the Dutch, who wished to maintain their economic and political dominance in the region, found the Habsburg offer displeasing, raising suspicions of England's motives, and the Duke's in particular. It was a position Marlborough desired, but in the name of Anglo–Dutch unity, it was one he refused.<89>