Downton Abbey started as a popular TV series , with six seasons , and then 2 feature films . Sally worked alongside designer Suzannah Buxton , and supervisor Dulcie Scott and the costume team, on Season one when the look and feel of the show was established , mainly working on the crowd costumes. She then went on to supervise the crowd in Seasons three and four, working with costume designer Caroline McCall, assistant designer Poli Kyriacou, and costume supervisor Heather Leat. Season 4 included elaborate scenes in the Royal Court , such as the presentation of Lady Rose McClare, and subsequent social events , which required a faithful representation of court costume on quite a grand scale, along with depicting the exciting and revolutionary social scene in 1920s London .