Complex sentence: In 1654 Charles Louis's brother, Prince Rupert, came to visit Heidelberg and soon Charlotte realised Rupert was in love with Marie Luise; in order to prevent nocturnal visits, Charlotte made Luise sleep in her bedroom.
Split into simpler sentences: In 1654 Charles Louis's brother, Prince Rupert, came to visit Heidelberg and soon Charlotte realised Rupert was in love with Marie Luise. In order to prevent nocturnal visits, Charlotte made Luise sleep in her bedroom.