Jalal al-Dawla had subsequently become involved in…

Rainald of Dassel, Archbishop of Cologne, had arrived in 1165 at the court of King Henry II of England at Rouen, to negotiate a German match for Matilda, the king’s eldest daughter by Eleanor of Aquitaine.

There was conflict during the negotiations, however, when Robert de Beaumont, second Earl of Leicester, had refused to greet the archbishop, alleging him to be a schismatic and a supporter of the anti-pope, Victor IV.

The original plan to match a daughter of Henry II with a son of Frederick I, Holy Roman Emperor, was abandoned, and instead Matilda left England in September 1167 to become the second wife of Henry the Lion, Duke of Bavaria and Saxony; the couple are married on February 1, 1168, at Minden Cathedral.

...Cumberland decides to cross the Weser south of Minden into the territory of the Electorate of Hanover itself, while he tries to ready his troops.

The main idea is to use the Weser as a natural defense line and to make it impossible for the French troops to cross the river.

Cumberland's forces continue to withdraw northwards.

The French pursuit is slowed by further problems with supplies, but they continue to steadily pursue the retreating Army of Observation.

In an effort to cause a diversion and provide some relief to Cumberland, the British plan an expedition to raid the French coastal town of Rochefort—hoping that the sudden threat will compel the French to withdraw troops from Germany to protect the French coast against further attacks.

Under Richelieu the French continue their drive, taking Minden, then...

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.

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.