He received his education from Eberhard von Danckelmann. After the premature death of his first wife, Landgraefin Elisabeth Henriette von Hessen-Kassel, he married Princess Sophie Charlotte of Hanover and by her fathered his successor.
In 1688 he succeeded his father and became Elector of Brandenburg. He was less dynamic than his father but still continued the build-up of Brandenburg-Prussia as a European power. Deeply religious, but physically and mentally unimpressive, he was determined to obtain the title of king. However, Emperor Leopold I witheld his consent, until he required Friedrich's support in the War of the Spanish Succession (1702-1714).
Friedrich preferred to leave the administration of his lands to others, first to his old tutor von Danckelmann (1688-1697) and later to Count Kolbe von Wartenberg (1697-1711). The latter was a flatterer and encouraged Friedrich's extravagances, lined his own pockets and left in turn the work to his Secretary of State.
In November 1700 Friedrich promised 8,000 soldiers and diplomatic support and in return he was allowed to crown himself as King 'in' Prussia, which he did in January 1701. He was said to be civilized, with a love of art, yet somewhat absurd. With the newest kingdom in Europe as well as the least important, he copied Louis XIV of France even to the point of appointing a mistress, a title most probably a nominal rather than an actual one as he preferred his wife by far. According to this wife, his second, his time was taken up with the 'infinitely little'; he overspent not only on pomp and display but
also on new buildings and palaces at Berlin, Charlottenburg and Potsdam.
As well, he built the University of Halle (1694), the Academy of Arts (1696) and the Academy of Sciences (1701); but these had been built at the urgings of his wife. The population rose and the royal
income doubled. The standing army increased from 30,000 to 50,000. In 1702 the Supreme Court of Appeal was established in Berlin and no more appeals to the Holy Roman Empire were allowed. Education was fostered and Brandenburg-Prussia enjoyed a reputation for religious toleration.After he lost his first two grandsons, he hoped to secure his house and, as a widower, he decided to marry again. It turned out to be a failure as his daughter-in-law was to produce another eleven children while he himself, at fifty years of age, was incapable of making love to his new wife, Sofie Luise, who having gone mad, appeared one night in his room in her underclothes. Not recognising the apparition, he presumed it to be a mythological White Lady supposed to appear whenever a Hohenzollern was about to die. "Weisse Frau," he cried then fell unconscious to die a few days later. Sofie Luise, a rather expensive lunatic, lived on for another twenty-two years.
 

Source: Leo van de Pas