Established the foundation for the unification of the Germany States, which would enable Germany emerge as a major world power at the start of the Twentieth Century.
The biggest failure of Fredrick the Great is that he never really understood power politics. Despite his tactical flair, he could never deliver a mortal blow to his enemies during the Seven Years War. Yes, Prussia survived, and Fredrick the Great cemented his reputation in the history books. But, after the war his kingdom was ravaged, farmlands destroyed, and his subjects were poorer. It was this failure, the war on many fronts, that lead future Prussian war planners and diplomats to the idea of avoiding a 2 front war. Prussia, while possessing excellent human resources, lacked material resources and money. A great military leader recognizes his nation's limitations and plans accordingly.
Accomplishments
After reaching the throne launched an unprovoked attack on the Austrian region of Silesia
Frederick built up Berlin as a cultural capital with grand buildings and rejuvenated the scientific work of the Berlin Academy.
In 1756 Europe’s longstanding alliances reshuffled during the so-called Diplomatic Revolution, which saw Austria allied with France and Russia as Prussia sided with England.
Frederick, who had used the years of peace to build and train an army of 154,000, launched a preemptive attack on Austria’s ally Saxony in 1756.