I'm interested if it was the actions of Prussia and it's leaders (Frederick The Great / Frederick William / Von Moltke) that saw Prussia rise to power, or if it was more luck/ good circumstances like the rapidly declining power of Austria. Or something else entirely. Thanks
There's a combination of reasons Prussia rose to prominence.
First of all, they had a series of very good rulers who reformed the tax base, built a strong army and generally rules Prussia very well.
Prussia used the decline of the Polish-Lithuanian Commonwealth and the Holy German Empire well. It gained Hinterpommern 1648, it wrested East Prussia from its vassal status of Poland-Lithuania 1657. 1715 it gaines parts of Vorpommern from Sweden. Then it managed to take Silesia after an exhaustive war against France, Austria and Russia 1765. Then it partook in the three partitions of Poland-Lithuania, gaining West Prussia/Danzig and Warsaw. It lost Warsaw to Russia, but gained the Rhineland after the Napoleonic war, as a reward for fighting Napoleon.
It was the relative military and economical superiority of Brandenburg/Prussia, the decline of Sweden and Poland-Lithuania and the ability to bounce back after fighting three of the primary five powers of the world during the Seven years' war that set Prussia on the status to become a grand power.