Months later, Mars hatches a plan to convince the American military the including women in their plans is in fact weakening the War effort.  The Duke of Deception has been grooming an American medical student who becomes Dr. Psycho.  Psycho harbors an intense hatred of women and is skilled in created phantasms similar to (and perhaps taught by) the Duke of Deception.  The Duke sets Psycho on a collision course with Wonder Woman but she ultimately defeats him.  Mars lambasts the defeated Duke and sentences him to serve in a women’s prison on Mars.   Enraged, he convinces them to women to overthrow Mars and his lieutenants, crowning him as King Deception.  Mars eventually escapes (Wonder Woman #5) and it is revealed several years later that Deceptions daughter Lya helped stage his overthrow (Comic Cavalcade #26).  Whether this was really his daughter or someone he called that is unclear.

After these initial efforts, the activities of the Duke of Deception during the war are generally unknown.  At some point during the War he has been reported to have participated in a series of efforts to help Nazi agents and to subvert American efforts using “The Disc of Mars”, but inconsistencies in this report raise questions as to its veracity (DC Special Series #9). Some poorly dated casework during the forties indicate the attempts to develop novel weapons, efforts which were thwarted by Wonder Woman and Queen Astra (Sensation #92). At some time during this period, she was also captured by the Duke who had feigned the capture of Hippolyta and expelled her into airless space, forcing her to device her characteristic red earrings, which could produce an oxygen bubble and keep her alive in a vaccumm (Wonder Woman #62). The Duke assisted as Mars launched a large scale effort to disrupt post-war peace efforts in 1949, including sending Wonder Woman through time and capturing a large population of the astral forms of many of her friends and taking them to Mars but this effort was again, ultimately defeated by Wonder Woman (Wonder Woman #34).

If anything, the Duke was even more active in the 1950’s.  In spring of 1951, he concocted a force tunnel between Mars and Earth, enveloping Washington DC.   The tunnel would allow access for his forces directly to the US Capitol, repelling anyone else who approached.  Wonder Woman traveled to Mars and with the aid of some Junior Justice Society Members, crushed the device creating the tunnel and saved Washington (Wonder Woman #47). In the summer of 1951, Mars made a significant effort to capture Paradise Island, breaking the taboo that men can never set foot.  An early foray led by Lord Conquest was repelled by Wonder Woman, leading the Duke to propose a duplicitous method, creating a second false Paradise Island to lure the Amazons to and himself as a fake Steve Trevor to distract Wonder Woman.  Success was close until the Duke’s own arrogance again foiled his plans (Sensation Comics #104).