The Leader

The Leader, was a parallel universe was the President of the Republic of Great Britain and the third incarnation of the Doctor. (NA: Timewyrm: Revelation)

Biography
This universe's version of the Second Doctor selected one of the bodies offered to him by the Time Lords after his trial. Like his counterpart, this version of the Doctor was banished to Earth in the late 20th century, where he became President of the Republic. (NA: Timewyrm: Revelation)

The Leader may have been at least partly responsible for his Earth's much more advanced technology. He died in the volcanic catastrophe that struck Great Britain in the aftermath of I-Day. (PDA: The Face of the Enemy)

Behind the scenes
BBC special effects designer Jack Kine 'played' the part of the Leader, as seen on the Big Brother-style UNITY IS STRENGTH poster in the Equipment Store (the Doctor's hut on the regular Earth timeline) and as a framed photograph on the wall of Brigade Leader Lethbridge-Stewart's office in Inferno. However, there is no on-screen evidence to suggest that the Doctor and the Leader had any connection.