June 14, 1866.

Prussia declared war on Austria's mismanagement of Holstein.

On the day of the declaration of war, the Prussian forces on the Western Front attacked the northern German states with lightning speed, and quickly took over the government organizations and railway hubs of these countries.

Due to the power and marriages of the Habsburgs in the Austrian Empire for many years, the German Confederation that supported Prussia was only a few small states with little military strength, and those that were slightly larger were on the side of Austria.

At the last meeting of the German Confederation, Prussia's vain attempt to solve the German question by force was rejected by many countries in the parliament.

This parliament made Prussia realize that it had basically no allies in the German region, so Prussia quickly declared war on these small northern German states after the war began.

At this time, Prussia was divided into two parts on the map, and in the middle were these small German states.

Most of these small countries were surrounded by Prussia, and they also ate the courage of bears and leopards, and dared to stand on the side of Austria, and the Prussian army, which did not speak of martial virtues, naturally did not negotiate with these small countries and directly launched a war to take over their power.

This time Prussia's determination to unify the whole of northern Germany and achieve a plan for small Germany was unprecedented, and these small countries could only be eliminated before they knew how to raise them.

Forget about the few countries in the south that have a little strength against Prussia, you small countries and free cities basically have no military strength, and you are in the hinterland of Prussia, and you dare to talk nonsense.

As the Prussian armies in the western theater marched directly into the North German states via the railway line, these small states were naturally powerless to stop them, and Prussia succeeded in seizing the power of its administration.

First of all, these small countries who do not know what to do are good and bad can be eliminated to prevent them from stabbing in the back, and at the same time, the traffic safety of Prussia's east-west railway network can be completely guaranteed.

The Bohemian Battlefield was the main battlefield of the Austro-Prussian War, where hundreds of thousands of troops were brought together by both sides, but Prussia was significantly more efficient than Austria.

One was that in 1862 Prussian von Rohn implemented several army reforms to ensure that all Prussian citizens were obliged to be drafted.

Prior to that, the size of the army, as it was determined earlier, did not take into account the growth of the population, thus making conscription unfair and unpopular.

While some Prussians remained in the army or reserve until the age of 40, about a third (and even more in some areas where the population had increased significantly due to industrialization) were assigned minimal tasks in their home army.

The introduction of universal conscription within three years increased the size of the active army and provided Prussia with a reserve equal in size and superior to that of Austria.

Prussia considered that if France under Napoleon III tried to intervene in the actions of the Prussians, they could also call up equal or more troops against Napoleon III's army through the reserve system.

Prussian conscription was an ongoing training and exercise, and some commanders of the Austrian army routinely sent the infantry home on permanent leave shortly after conscription, leaving only a group of permanent soldiers to stay in the barracks for long periods of time or to perform their duties.

As a result, Austrian conscripts had to train almost from scratch when they were recalled to their units after the outbreak of war.

So the Prussian army was better trained and disciplined than the Austrian army, especially in terms of infantry.

While the Austrian cavalry and artillery were just as well trained as their Prussian counterparts, and Austria had two elite heavy cavalry divisions, since the Napoleonic Wars had advanced in weaponry and tactics, and cavalry charges had become obsolete.

The Prussian army was based locally and organized in military districts, each of which contained a corps headquarters and its constituent units. Most of the reservists lived near their regimental warehouses and could be mobilized quickly.

Austria's policy was to ensure that troops were stationed far from home in order to prevent them from participating in the separatist rebellion.

Conscripts on leave or reservists who were recalled to their units during mobilization faced a journey that could take weeks to report to the unit, which made the mobilization in Austria much slower than that of the Prussian army.

At the same time, the railway system in Prussia was much more developed than in Austria. Railways made it possible to supply more troops than ever before and allowed troops to move quickly within friendly territory. A more efficient Prussian railway network allowed the Prussian army to concentrate more quickly than the Austrians.

Reviewing his plans for Rune, Moltke said: "We had an incalculable advantage in being able to transport our 285,000 field troops to 5 railway lines and concentrate them almost in 25 days. …… Austria has only one railway line to assemble 200,000 people, it will take her 45 days. ”

Moltke Sr. also said earlier, "There is nothing more popular than having now the war that we must have." ”

Austrian army under Ludwig von Benedek in Bohemia.

Previously it was considered to enjoy the advantage of a "central position", since they were able to concentrate on launching continuous offensives along the border areas.

But the faster concentration of Prussia offset this advantage. When the Austrians were fully assembled, they were concentrating on one Prussian army and could not prevent the other two Prussian armies from attacking their flanks and rear, threatening their lines of communication.

In the south, the presence of the Italians forced Austria to disperse its forces to fight against the Kingdom of Italy, and even Austria had withdrawn from Venesia on its own initiative.

The war situation was not in Austria's favor from the beginning, and the decrepit Austria had to ask Napoleon III for help, but Napoleon III still underestimated Prussia, and he agreed to Austria's demands, but did not intervene.

On June 23, the Prussian army reached the line from Zavidouv to Chitau.

On 26 June, the Battle of the Yunna River took place between the Prussian and Austrian armies.

Moltke, the chief of staff of the Prussian army, carefully planned the battle formation and concentrated firepower to attack Austria. When the Austrians concentrated their invasion of Silesia, he moved his troops to Saxony and Bohemia, where he joined King Wilhelm I, who had already assembled a large army there.

On 3 July, the Prussian army went on a major offensive and defeated the Austrians at the Battle of Knigretz (also known as the Battle of Sadowa). The Austrian army had an advantage in numbers, but the number of dead and wounded was seven times that of the Prussian army, all because the Prussian army was well-equipped and strategically appropriate.

With the exception of Saxony, the influence of other states on the war was limited. Hanover's army defeated the Prussian army at the Battle of Batlangensalza on 27 June, but was soon besieged by the large army and surrendered. The Prussian army confronted Bavaria head-on on the Main and fought at Nuremberg and Frankfurt. Würzburg in Bavaria was besieged by the Prussian army, but did not surrender until the armistice.

Austria took Italy by surprise, defeating the Italians at the Battle of Custazza on 24 June and the Battle of Lisa on 20 July (Lisa in present-day Vis Croatia).