War

June 14, 1866.

Prussia declared war on Austria, citing Austria's mismanagement of Holstein.

On the same day war was declared, Prussian forces on the Western front swiftly attacked the northern German states, rapidly taking over their government organizations and railway hubs.

Due to the long-standing prestige and intermarriages of the Habsburg family of the Austrian Empire, only a few small states with virtually no military power supported Prussia. The larger states sided with Austria.

In the previous German Confederation assembly, Prussia's attempt to resolve the German question through force was rejected by many nations present.

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

At this time, Prussia was divided into two parts on the map, with these scattered small German states in between.

Most of these small states were surrounded by Prussia and had the audacity to stand with Austria. The Prussian army, lacking any sense of martial virtue, naturally did not negotiate with these small states and directly launched wars to take over their regimes.

Prussia's determination to unify all of northern Germany and achieve the "Lesser German" plan this time was unprecedented. If these small states refused to cooperate, they would simply be eliminated.

It was one thing for the few slightly powerful states to the south to oppose Prussia, but these small states and free cities, with virtually no military strength and located in Prussia's heartland, dared to make such a fuss.

As Prussian forces on the Western front advanced directly into the northern German states via railway lines, these small states were naturally powerless to resist, and Prussia successfully seized control of their administrative powers.

First, eliminate these ungrateful small states to prevent them from stabbing us in the back, and at the same time, thoroughly guarantee the safety of Prussia's east-west railway network.

The Bohemian front was the main battlefield of the Austro-Prussian War. Hundreds of thousands of troops from both sides converged here, but Prussia's efficiency was clearly higher than Austria's.

One reason was that in 1862, Prussia's von Roon implemented several army reforms, ensuring that all Prussian citizens had an obligation to be conscripted.

Before this, the army's size had been determined earlier and did not account for population growth, making conscription unfair and unpopular.

Although some Prussians remained in the army or reserves until the age of 40, about one-third of them (even more in areas with significant population growth due to industrialization) were assigned minimal duties in their local regiments.

Within three years, universal conscription was implemented, increasing the size of the active army and providing Prussia with a reserve force comparable in size to Austria's, but superior.

Prussia considered that if France, under Napoleon III, attempted to intervene in Prussia's actions, they could also mobilize an equal or greater number of troops through the reserve system to counter Napoleon III's army.

Conscription in Prussia involved continuous training and exercises, whereas some Austrian army commanders routinely granted permanent leave to conscripts shortly after they joined, sending them home and keeping only a group of long-term soldiers in barracks or on duty.

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

As a result, the Prussian army was better trained and more disciplined than the Austrian army, especially in the infantry.

Although Austrian cavalry and artillery were as well-trained as their Prussian counterparts, and Austria possessed two elite heavy cavalry divisions, cavalry charges had become obsolete due to advancements in weaponry and tactics since the Napoleonic Wars.

The Prussian army was organized by military districts, with each district containing a corps headquarters and its constituent units. Most reservists lived near their regimental depots, allowing for rapid mobilization.

Austria's policy was to station troops far from their homes to prevent them from participating in separatist rebellions.

Conscripts on leave or reservists recalled to their units during mobilization faced journeys that could take weeks to report to their units, making Austria's mobilization much slower than that of the Prussian army.

Meanwhile, Prussia's railway system was more developed than that within Austria. Railways made it possible to supply larger armies than ever before and allowed for rapid troop movements within friendly territory. The more efficient Prussian railway network enabled the Prussian army to concentrate faster than the Austrians.

Moltke, reflecting on his plans with Roon, stated: "We have an immeasurable advantage in being able to transport our 285,000 field troops on five railway lines and concentrate them in almost 25 days. ... Austria, with only one railway line, would take 45 days to concentrate 200,000 men."

Old Moltke had also said earlier, "Nothing is more welcome than the war we now have to wage."

The Austrian army in Bohemia was led by Ludwig von Benedek.

They were previously thought to have the advantage of a "central position," enabling them to concentrate their forces for successive attacks along the border region.

However, the faster-moving Prussian concentration negated this advantage. By the time the Austrians were fully assembled, they were unable to prevent two other Prussian armies from attacking their flanks and rear, threatening their supply lines, when they were concentrating against one Prussian army.

Furthermore, in the south, the presence of the Italians forced Austria to divert troops to fight the Kingdom of Italy, and Austria had even voluntarily ceded Venetia.

The war situation was unfavorable to Austria from the outset. The aging Austrian Empire had to seek aid from Napoleon III, but Napoleon III underestimated Prussia. He agreed to Austria's request but was slow to intervene.

On June 23, Prussian forces massed along the line from Zawidów to Zittau.

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

The Prussian Chief of Staff, Old Moltke, meticulously planned the battle formations, concentrating his firepower on Austria. When the Austrian army concentrated its forces to invade Silesia, he redeployed his troops to Saxony and Bohemia to rendezvous with King Wilhelm I of Prussia, who had already assembled a large army there.

On July 3, the Prussian army launched a major offensive, defeating the Austrian army at the Battle of Königgrätz (also known as the Battle of Sadowa). Although the Austrian army had a numerical advantage, their casualties were seven times that of the Prussian army, due to the Prussian army's superior equipment and sound strategy.

Apart from Saxony, the other states had a limited impact on the war. The Hanoverian army defeated the Prussian army at the Battle of Langensalza on June 27 but soon surrendered after being surrounded by a large army. Prussian forces clashed head-on with Bavaria on the Main River, fighting in Nuremberg and Frankfurt. Würzburg in Bavaria was besieged by the Prussian army but did not surrender until the armistice.

Austria, however, had an unexpected success in its campaign against Italy, defeating the Italian army at the Battle of Custoza on June 24 and in the naval Battle of Lissa (Lissa is in present-day Vis, Croatia) on July 20.