Sid was the owner of the Old Rogue, a café in Catford. When Arkinen used his understanding device with the intention to destroy Earth, the beam was zoomed in and it him Sid. Jamie McCrimmon then pushed Arkinen into the beam and he swapped bodies with Sid. So, with those around him believing him to be Arkinen, Sid was in control of of a large empire. Unlike Arkinen, he worked for good and came to be known as a benevolent ruler. Statues of him were built on several planets. Meanwhile, Arkinen lived out Sid's life on Earth, working in the Old Rogue. (PROSE: The Old Rogue)