Maria Theresa's diplomats have actively begun to establish an anti-Prussian coalition after securing French neutrality.

Austria's actions have alerted Frederick II, who decides to strike first by invading Saxony, one of the small German states in league with Austria, commencing what will be known as the Seven Years' War.

Frederick, a believer in the pre-emptive strike, leads Prussian troops across the border of Saxony, one of the small German states in league with Austria, on August 29, 1756, against the advice of his British allies.

He intends this as a bold preemption of an anticipated Austro-French invasion of Silesia.

Frederick has three goals in his new war on Austria.

First, he will seize Saxony and eliminate it as a threat to Prussia, then use the Saxon army and treasury to aid the Prussian war effort.

His second goal is to advance into Bohemia, where he might set up winter quarters at Austria's expense.

Thirdly, he wants to invade Moravia from Silesia, seize the fortress at Olmütz, and advance on Vienna to force an end to the war.

Accordingly, leaving Field Marshal Count Kurt von Schwerin in Silesia with twenty-five thousand soldiers to guard against incursions from Moravia and Hungary, and leaving Field Marshal Hans von Lehwaldt in East Prussia to guard against Russian invasion from the east, Frederick sets off with his army for Saxony.

The Prussian army marches in three columns.

On the right is a column of about fifteen thousand men under the command of Prince Ferdinand of Brunswick.

On the left is a column of eighteen thousand men under the command of the Duke of Brunswick-Bevern.

In the center is Frederick II himself, with Field Marshal James Keith commanding a corps of thirty thousand troops.

Ferdinand of Brunswick is to close in on the town of Chemnitz.

The Duke of Brunswick-Bevern is to traverse Lusatia to close in on Bautzen, while Frederick and Keith make for Dresden.

...the Saxon army takes up a strong defensive position near Pirna, and Frederick has no option but to isolate and try to starve them into surrendering.

Realizing that the siege will take some time, he is compelled to leave a covering force around Pirna and head south through the rough Mittel-Gebirge of northern Bohemia to establish a winter base in the rich Bohemian plain.

Neither the Saxon nor the Austrian army is ready for war.

Following Frederick's occupation of the Saxon capital, Dresden, on September 9, ...

An Austrian army under Field Marshal von Browne has prepared a fortified base at Budin to block any Prussian moves out of the Mittel-Gebirge.

Browne has been in secret communication with the Saxon prime minister, Heinrich Count Bruhl, and has planned a rescue mission up the right bank of the Elbe to Königstein, near Pirna, to help the Saxon army escape across the river and join its allies.

On the 28th, Browne receives an enthusiastic agreement from Bruhl on his proposal; the date of the rendezvous of the two forces is to be the night of 11/12 October.

Frederick and his twenty-eight thousand men are meanwhile making their way through the Mittel-Gebirge toward the Bohemian plain.

Browne's intelligence tells him that the Prussians will exit from the mountains at Lobositz (present Lovosice in the Czech Republic), a few miles northwest of his fortified base at Budin.

He recalls his small relief force up the Elbe and races with thirty-three thousand men up to Lobositz on the 28th to lay an ambush for Frederick as he debouches from the narrow passes of the mountains.

Frederick prevents the isolated Saxon army from being reinforced by an Austrian army under General von Browne at the Battle of Lobositz on October 1, 1756.

Both sides lose about the same number of men each, about twenty-nine hundred, which is more severe for the initially smaller Prussian army.

Still shaken in the days following the battle, Frederick had decided his only political option was to proclaim Lobositz as a victory by eighteenth century rules of combat (since Browne had left the field of battle).

However, Browne had done exactly what he had set out to do: stop Frederick at Lobositz and cover his own crossing of the Elbe further upstream to go and rescue the Saxon army at Pirna.

Indeed, Frederick, though he sat on the "field of victory", never advanced beyond Lobositz and within two weeks had ordered a general retreat back into Saxony.

So, strategically, with his army intact, Bohemia safe, and his way north to the Saxons unhindered, Browne can be thought of as having won a strategic victory at Lobositz.

In the aftermath, Browne had led his rescue mission north, with a picked force of eight thousand men, down the right (eastern) bank of the Elbe.

Though suffering from tuberculosis himself and coughing up blood, Browne had driven himself and his men through rain and mountain passes to arrive at his rendezvous point, Königstein, at precisely the date he promised the Saxons, October 11.

However, the Saxons had not lived up to their own promise to cross the Elbe at Königstein on that date, and procrastinated.

The dissembling Count Bruhl had been negotiating with the Prussians for a better deal and kept sending disingenuous pleas for patience to Browne.

The Prussians, by the fourteenth finally alerted to the presence of the Austrians waiting on the right bank opposite Königstein, had crossed with a blocking force themselves.

Bruhl and the Saxon King Augustus III, as well as the senior Saxon general staff, had by this time surrendered the entire Saxon army to Frederick, and had negotiated some fairly lucrative compensation arrangements for themselves.

The Saxon regiments are all swiftly and forcibly incorporated whole into the Prussian army, an act that sparks widespread protest even from Prussians.

This political-military coup will prove short-lived, however, for most of the infantry regiments will defect within a year, and the Saxon cavalry regiments take it upon themselves (including Count Bruhl's own chevauleger regiment) to escape and fight intact for the Austrians.

Prussia's attack on neutral Saxony has caused outrage across Europe and leads to the strengthening of the anti-Prussian coalition.

The only significant Austrian success is the partial occupation of Silesia.

Frederick's early successes, far from being easy, have proved indecisive and very costly for Prussia's smaller army.

This leads him to remark that he does not fight the same Austrians as he had during the previous war.

Frederick faces widespread criticism for his attack on neutral Saxony and for his forcible incorporation of the Saxon forces into the Prussian army following the Siege of Pirna in October 1756.

Britain had been surprised by the sudden Prussian offensive but now begins shipping supplies and six hundred and seventy thousand pounds (equivalent to eighty nine million, nine hundred thousand dollars in 2016) to its new ally.

Despite the huge disparity in numbers, the year has been successful for the Prussian-led forces on the continent, in contrast to the British campaigns in North America.

The Prussian army had marched in four columns over the mountain passes separating Saxony and Silesia from Bohemia in early spring, entering the kingdom on April 18. 

The four corps are to unite at the Bohemian capital of Prague. 

Though risky, because it exposes the Prussian army to a defeat in detail, the plan will succeed.

It is not in the nature of Frederick the Great, nor in his military strategy, simply to sit back and defend.

After having forced the surrender of Saxony in the 1756 campaign, he had spent the winter devising new plans for a defense of his small kingdom, and had begun drawing up plans for another bold stroke against Austria.