At the end of the 17th century the German states were weak and divided. Only one, Brandenburg-Prussia, had a ruler with a vision of the future and the determination to achieve his ambitions. This was Frederick William, the Great Elector (1640-1688). He completely unified the scattered Hohenzollern possessions by creating a ruthlessly efficient administration. He recruited Dutch engineers to drain the marshes and swamps. He also welcomed French, German and Swiss Protestant refugees from religious persecution. With state aid, these refugees rapidly settled in their new country and helped Frederick William create an economic revolution. Factories were built and a postal system established.

Everyone, nobles and commoners alike, paid taxes to support a small, but efficient, army. In 1675 the Great Elector used this army to challenge Swedish power by marching into Pomerania ( a German state on the southern shores of the Baltic controlled by Sweden) and defeating the Swedes. This victory was a little premature because, in 1678, Sweden's ally, Louis XIV, forced Frederick William to retire from Pomerania. Frederick William, however, was ready to be patient and wait for the next opportunity.

The chance came when the great Elector was succeeded by the Elector Frederick III (1688-1713). He managed to obtain from the Emperor the title of King of Prussia. In 1701 the new king, now titled Frederick I, King of Prussia, established his royal court at Königsberg. (During the official ceremony Frederick flew into a rage because his queen took snuff during the service and, each time he took a drink, a nine cannon salute was fired). He was described as being "great in little things", which was meant as criticism. However, his strict control of finance, his creation of a fine secondary school system and his welcoming of persecuted Protestants from all over Europe established a Prussian state which would soon rival Austria as the great German power.