Complex sentence: When Marguerite refused Le Gris attempted to take her by force and, with the help of Louvel, raped her on the bed in her chamber before leaving, threatening her with violence if she told of the encounter.
Split into simpler sentences: When Marguerite refused, Le Gris attempted to take her by force and with the help of Louvel, raped her on the bed in her chamber before leaving. As he departed, he threatened her with violence if she told of the encounter.