The Longcoats are Azkadellia's Royal Troops. Stereotypical evil henchmen, they get their names from the long, black coats which they wear. Describing their dark appearance, a character in the miniseries refers to them as "stormtrooper meets leather bar." Their appearance and attitude is also akin to members of the SS, Hitler's secret police. They could be seen as parallels of the Winkies in the original story
As their name suggests, they wear long coats. They were instrumental in hunting down the Tin Men, the last defenders of the old order, who were the old police force.