Robert Graves died on December 7, 1985 at the age of 90.
he goes into a Radiation chamber or something to save donnas Grandad and dies... after that he goes and visits all his companions
The Spaceman in Series 6 episode 1 killed a future version of the 11th Doctor.
Yes he was killed in the impossible astronaut
Presuming you mean David Tennant, there isn't a set date. But in the 2009 specials of Doctor Who, David Tennant will appear in all of them so therefore the last shall be his regeneration. It is...