By marrying Frederick on 8 October 1684, she became Electress of Brandenburg in 1688, and after the elevation of Brandenburg-Prussia to a kingdom in 1701, she became the first Queen in Prussia. Her only child to reach maturity became King Frederick William I of Prussia. Her husband was so much in love with her that while he had an official mistress, Catharina Rickert, at his palace — in imitation of Louis XIV — he never made use of her services; however, his feeling was not mutual.