Sheckil was a Human male hailing from the Mandalorian planet Concord Dawn and the twin brother of a famous mercenary. A former warrant officer on his homeworld, Sheckil served the Galactic Empire as a lieutenant during the Galactic Civil War. In early 3 ABY, in the wake of the Battle of Hoth, Sheckil accompanied the Dark Lord Darth Vader and a stormtrooper occupation force during the clandestine seizure of the Bespin mining colony of Cloud City in a scheme to capture Han Solo, Princess Leia Organa, and, ultimately, Luke Skywalker of the Rebel Alliance. The Empire forced city Baron Administrator Lando Calrissian into accepting a deal in which the Empire would not permanently occupy Cloud City in return for Calrissian's compliance in helping to apprehend the Rebels.