In Downton Abbey, Michael Gregson is the newspaper editor linked romantically to Lady Edith. He edits the society magazine The Sketch and first contacts Edith after she publishes writing supporting women's voting rights.
Gregson is already married, but his wife, Lizzy, has been institutionalized and English law does not allow him to divorce her on those grounds. He and Edith nevertheless fall in love. Hoping to marry her legally, Gregson plans to become a German citizen, since German law would allow him to divorce.
He disappears in Munich after becoming involved in a confrontation with men associated with the early Nazi movement. Edith later learns that he was probably killed during the 1923 Beer Hall Putsch. His death leaves her pregnant with their daughter, Marigold, and she eventually inherits his publishing business.
A common mix-up is Bertie Pelham, whom Edith marries later. Charles Blake and Anthony Strallan are also Edith's suitors or romantic connections, but neither is the editor in this question.