Catherine of Aragon
Catherine Howard and Anne Boleyn were first cousins and were both beheaded. Jane Seymour was second cousin to both Anne Boleyn and Catherine Howard. Several of Henry's wives worked in service to another wife, typically as a lady-in-waiting: Anne Boleyn served Catherine of Aragon, Jane Seymour served both Catherine of Aragon and Anne Boleyn, and Catherine Howard served Anne of Cleves.