After the death of the queen, Philippa went to the service of Costanza of Castile and John of Gaunt, the Duke of Lancaster. Following Costanza's death in 1394, John wed his mistress, Katherine, who was Philippa's sister. This connection significantly increased the Chaucers' status in society. Philippa was much in favor in court as a lady-in-waiting and her husband continued to elevate his reputation. He worked as a Controller of Customs and royal agent. Due to the varying nature of their jobs, Chaucer and Philippa were often forced to spend much of their time apart. This may explain why very little is known about their marriage.