The western German-speaking states of Europe have been a major theater of the Seven Years' War since 1757, when the French had launched an invasion of Hanover.

This had culminated in a decisive victory for the French at the Battle of Hastenbeck and the attempted imposition of the Convention of Klosterzeven upon the defeated allies: Hanover, Prussia and Britain.

Prussia and Britain had refused to ratify the convention and, in 1758, a counter-offensive commanded by Ferdinand had seen French forces first driven back across the Rhine, then beaten at the Battle of Krefeld.

The Prussian port of Emden had also been recaptured, securing supply from Britain.

As the campaigning season of 1759 opens, Prince Ferdinand steals a march on the French by moving out of winter quarters in late March.

His destination is Frankfurt, where the French have a base on the Main River.

The intent is to drive the French out of Westphalia and seize the initiative for the allies.

By the end of the month, his army comprises some twenty-seven thousand men grouped into three divisions.

One is commanded by Ferdinand himself, one by Prince Isenburg, and the third by the Duke of Holstein-Gottorp.

Operations commence with the seizing of Fulda and Meiningen from troops of the Imperial army under Field Marshal von Zweibrücken.

As the Imperial army retreats into Bohemia, Ferdinand moves into Hesse hoping to fall upon Broglie's corps before it can be reinforced.

Broglie, however, is able to reinforce his corps with a contingent of Saxons under the General von Dyhrn (Dyherrn) along with other French regiments that he is able to assemble.

He places his small army at the fortified town of Bergen and awaits developments.

Ferdinand's army arrives on the field of battle piecemeal.

Ferdinand himself accompanies the vanguard, commanded by the Erbprinz.

As Ferdinand mistakenly believes that the French had not yet fully deployed, he orders an immediate attack, choosing not to wait for the other two divisions.

Despite the long odds, by eight o'clock the town of Vilbel has been seized by Freytag's light infantry and the "Am Hohen Stein," another low hill located east of the "Berger-Warte," has been occupied.

Perceiving that Bergen is the key to the position, by 8:30 Ferdinand has ordered an assault on this position.

The initial allied attack is successful, driving the French infantry from the hedges and orchards that they occupy and back into the town.

Broglie now begins to feed in reinforcements, which turn the tide against the allies, driving them back.

At ten o'clock Prince Isenburg's division arrives.

Isenburg pitches into the fray, once again driving the French troops back into Bergen.

Broglie immediately counterattacks with more fresh regiments that he has fed in from his reserve, disordering the allies and driving them back once more.

Isenburg himself is killed while trying to rally his men.

It is with difficulty that Ferdinand himself is able to restore order to his troops.

At this point, the battle begins to cool off.

As Broglie brings his reserve and his cavalry forward, Ferdinand is able to gauge the size of his opponent's army.

Furthermore, the French artillery is finding its range and forcing the allied army back up the "Am Hohen Stein."

As Holstein-Gottorp's division finally makes it onto the field, preparations for another attack are abandoned and the battle turns into an artillery duel that lasts until the fall of night, when the allies withdraw.

Although it is a clear French victory, Broglie does not aggressively pursue Ferdinand, who is able to slip away with his army back toward Minden.

This is Ferdinand's darkest moment, and even his brother in law, Frederick the Great, commiserates with him to try to boost his morale.

Ferdinand will recover, however, and redeem himself and his army later in the same year at the Battle of Minden.

Allied casualties amount to four hundred and fifteen dead, seventeen hundred and seventy wounded, and one hundred and eighty-eight missing.

The French lose five hundred dead and thirteen hundred wounded.

The British government, which had previously been opposed to any direct involvement on the continent, takes the opportunity of the 1758–59 winter break in fighting to send nine thousand British troops to reinforce Ferdinand.

The French crown also sends a reinforcing army, under Contades, hoping this will help to secure a decisive victory, swiftly concluding the costly war, and forcing the Allies to accept the peace terms France is seeking.

In an attempt to defeat the French before their reinforcements arrive, Ferdinand has decided to launch a fresh counter-offensive, and had quit his winter quarters early.

In April, however, Victor-François, Duke de Broglie and the French had withstood Ferdinand's attack at the Battle of Bergen, and de Broglie had been promoted to Marshal of France.

Ferdinand had been forced to retreat northwards in the face of the now reinforced French army.

Contades, senior of the two French marshals, had resumed the advance, occupying a number of towns and cities including the strategic fortress at Minden, which had fallen to the French on July 10.

Ferdinand is criticized for his failure to check the French offensive.

His celebrated brother-in-law, Frederick the Great, is reported as having suggested that, since his loss at Bergen, Ferdinand had come to believe the French to be invincible.

Irrespective of any presumed crisis of confidence, however, Ferdinand does ultimately decide to confront the French, near Minden.

Contades has taken up a strong defensive position along the Weser around Minden, where he has paused to regroup before he continues his advance.

He initially resists the opportunity to abandon this strong position to attack Ferdinand.

Ferdinand instead formulates a plan that involves splitting his force into several groups to threaten Contades' lines of supply.

Perceiving Ferdinand's forces to be over-extended, Contades thinks he sees a chance for the desired decisive victory.

He orders his men to abandon their defensive encampments and advance into positions on the plain west of Minden during the night of July and early morning of August 1.

The reaction in France to the result of the Battle of Minden is severe.

The Duc de Choiseul, the French Chief Minister, writes "I blush when I speak of our army. I simply cannot get it into my head, much less into my heart, that a pack of Hanoverians could defeat the army of the King".

To discover how the defeat had occurred and to establish the general condition of the army, Marshal d'Estrées is sent on a tour of inspection.

Marshal de Contades is subsequently relieved of his command and replaced by the Duc de Broglie.

Michel Louis Christophe Roch Gilbert Paulette du Motier, Marquis de La Fayette and colonel aux Grenadiers de France, had been killed when he was hit by a cannonball in this battle.

La Fayette's son, Gilbert du Motier, marquis de Lafayette, is not even two years old at this time.

Jean Thurel, the long-serving fity-nine-year-old French fusilier, had been severely wounded, receiving seven sword slashes, six of them to the head.

Ferdinand's cavalry commander, Lieutenant General Lord George Sackville, is accused of ignoring repeated orders to bring up his troopers and charge the enemy until it was too late to make any difference.

In order to clear his name he requests a court martial, but the evidence against him is substantial and the court martial declares him "...unfit to serve His Majesty in any capacity whatsoever."

Sackville will later reappear as Lord George Germain and bear a major portion of the blame for the outcome of the American Revolution while Secretary of State for the Colonies.

In Britain the result at Minden is widely celebrated and is seen as part of Britain's Annus Mirabilis of 1759 also known as the "Year of Victories", although there is some criticism of Ferdinand for not following up his victory more aggressively.

When George II of Great Britain learns of the victory, he awards Ferdinand £20,000 and the Order of the Garter.

Minden further boosts British support for the war on the continent, and the following year a "glorious reinforcement" will be sent, swelling the size of the British contingent in Ferdinand's army.

Contades, in an exception to the norm for the era, places his artillery in the center protected only by the cavalry, with his infantry on either flank.

The battle begins on the French right flank, where Marshal de Broglie, who commands the reserve, begins an artillery duel against the allied left.

The decisive action of the battle takes place in the center, famously due to a misunderstanding of orders.

Friedrich von Spörcken's division, composed of the infantry of the British contingent of the allied army (two brigades under Earl Waldegrave and William Kingsley) and supported by the Hanoverian Guards, actually advance to attack the French cavalry.

It is reported that they had been ordered "to advance [up-]on the beating of drums" (i.e., advance when the signal drums begin to beat,) misunderstanding this as "to advance to the beating of drums" (i.e., advance immediately while beating drums.)

Since the French cavalry is still in its ranks and the famous 'hollow square' has not yet been developed, it is assumed by all that the six leading British regiments are doomed.

Despite being under constant artillery fire, the six regiments (soon supported by two Hanoverian battalions), by maintaining fierce discipline and closed ranks, drive off repeated cavalry charges with musket fire and inflict serious casualties on the French.

Contades reportedly said bitterly, "I have seen what I never thought to be possible—a single line of infantry break through three lines of cavalry, ranked in order of battle, and tumble them to ruin!"(Stenzel, Gustav Adolf Harald (1854). Geschichte des Preussischen Staats. Fünfter Band 1756–1763 (in German). Hamburg. Trans. Carlyle (1869): 44.)

Supported by the well-served British and Hanoverian artillery, the entire allied line eventually advances against the French army and sends it fleeing from the field.

The only French troops capable of mounting any significant resistance are those of de Broglie, who forms a fighting rear guard.
 
Prince Ferdinand's army suffers nearly twenty-eight hundred men killed and wounded; the French lose about seven thousand men.

In the wake of the battle the French retreat southwards to Kassel.

The defeat ends the French threat to Hanover for the remainder of that year.

Lafayette has learned that the Continental Congress lacks funds for his voyage; hence, he acquires the sailing ship Victoire with his own money, for 112,000 pounds.

He journeys to Bordeaux, where Victoire is being prepared for her trip, and sends word asking for information on his family's reaction.

The response, including letters from his wife and other relatives, throws Lafayette into emotional turmoil.

Soon after departure, he orders the ship turned around and returns to Bordeaux, to the frustration of the officers traveling with him.

The army commander here orders Lafayette to report to his father-in-law's regiment in Marseilles.

De Broglie, who hopes to become a military and political leader in America, meets with Lafayette in Bordeaux and persuades him that the government actually wants him to go.

This is not true, though there is considerable public support for Lafayette in Paris, where the American cause is popular.

Lafayette wants to believe it, and pretends to comply with the order to report to Marseilles, going only a few miles east before turning around and returning to his ship.

Victoire sets sail for the United States on April 20, 1777.

The Assembly at Versailles remains ignorant of most of the Paris events, but eminently aware that Marshal de Broglie stands on the brink of unleashing a pro-Royalist coup to force the Assembly to adopt the order of June 23, then to dissolve.

The vicomte de Noailles apparently first brings reasonably accurate news of the Paris events to Versailles.

M. Ganilh and Bancal-des-Issarts, dispatched to the Hôtel de Ville, confirm his report.

By the morning of July 15, the outcome appears clear to the king as well, and he and his military commanders back down.

Among the first nobles to leave Paris are the comte d'Artois (the future Charles X of France) and his two sons, the prince de Condé, the prince de Conti, the Polignac family, and (slightly later) Charles Alexandre de Calonne, the former finance minister.

They settle at Turin, where Calonne, as agent for the count d'Artois and the prince de Condé, will begin plotting civil war within the kingdom and agitating for a European coalition against France.