Doctor.... Who?

The Doctor's journey from Gallifrey to Earth has spanned over hundreds of years. Since he is 945? 947? IDK it varies in each episode. Well, the Doctor has had lots of time to gain wisdom and he realized, sometime or other that our little planet filled with little people is the place for him. Ever since he left Gallifrey in the TARDIS things have basically just gone bonkers for him. I guess this will be hard for me, talking about his life as if is was a timeline, but since he's a Timelord, his story is anything but a linear one. I'll just go through the main events.
Firstly, his adventures all kicked off when he was just a little tike (about 302) when he stole a TARDIS from a stock-pile of TARDISes after the type 40s had been decommissioned. Like all TADISes this type 40 could travel through time and space, but it had a certain... spice to it's mechanical soul. This is why the Doctor decided to keep it when he had the option of acquiring the newer type of TARDIS. It is commonly known that this spaceship never takes the Doctor where he wants to go, but where he needs to go. Therein  lies the premise for his heroism. Always zooming about in his time machine saving peoples' lives and stopping alien invasions on Earth. "The mad man with a box."
Second, is his feud with the Master, who is the antithesis of the Doctor. Both grew up together on Gallifrey right around the time when the academy was initiating a new ceremony... gazing into the Untempered Schism. It was known that the schism had 3 after effects. 1) you would run away screaming 2) become a genius 3) or go absolutely coocoo for coa coa puffs. The Doctor, well, he ran. The Master, however mmm, let's just say that's when the drumming started, but that's whooole nother story. Anyway, the Master went crazy and is always trying to foil the Doctor. Their feud has lasted for ages with the Doctor always doing the right thing and saving the planet from the Master's horrible mischief.
The last point in time that was incredibly significant in the Doctor's long life was the day he killed his own race... The Daleks of the planet Skaro were fighting the Timelords of Gallifrey and if ever there was or will be a more detestable race full of anger, greed, and destruction, multiply them by 1000 and you'll have the Daleks. They were trying to take over the universe... their favorite word is "EXTERMINATE!!!" so let me rephrase that: the wanted to take over the universe and exterminate every other race so that the Daleks could reign supreme. The Timelords tried to stop them and things happend, circumstances evolved and the Doctor has to lock EVERYONE in a time bubble (A time bubble occurrs when an individual meets their past or future self under certain circumstances. This results in time being frozen save for the individual who caused the bubble. The bubble would quickly deteriorate and normal time resumes.)He saved the universe at a tremendous cost and later on when the timelords get out of the bubble (through the Master) they're pretty pissed off.
Having to make sacrifices is what the Doctor does best, not that city of Pompeii is very greatful for that, but hey, he does his best. He has faced daleks, suntarens, cybermen, atraxi, weaping angels, the master, the rest of the timelords, the vashta nerada, satan himself and so many other horrific beings throughout time. Yet the most dangerous thing in existance is the doctor himself. If he ever turned against the earth and its inhabitants, or even the whole universe, we would never stand a chance.