Guardian of the Solar System

Guardian of the Solar System was a title held by Mavic Chen in the year 4000. The Guardian ruled Earth and its dominions. He had complete control over the Space Security Service based in Central City on the planet Earth. (TV: The Daleks' Master Plan)

In 4041, 41 years after Mavic Chen's demise, the title of Earth's head of state was again President of Earth. (COMIC: Return of the Klytode)

The Eighth Doctor explained to Samantha Jones that the Guardian of the Solar System's role in the Galactic Federation in 3999 as analogous to US President Bill Clinton's role in the United Nations in 1997. (PROSE: Placebo Effect)