The Doctor's regenerations (The Curse of Fatal Death)

After being killed by a stray Dalek laser, lying on the floor, the Ninth Doctor began to regenerate. The Master stated that the Doctor was only on his ninth body, and that he had "many many more". (TV: The Curse of Fatal Death)

Ninth Doctor's regeneration
The Ninth Doctor started to regenerate after being killed by a stray Dalek laser. His final moments were used to talk to his partner Emma in perfect Tersuran. After he died, the Master stated that regeneration was the miracle of the Time Lords which was proceeded by the Ninth Doctor's change into the Tenth Doctor. (TV: The Curse of Fatal Death)

Tenth Doctor's regeneration
Shortly after admiring his new body, the Tenth Doctor sent Emma to the TARDIS to get some champagne to celebrate their new life together and began work on repairing the Zectronic Beam Controller. An electrical spark triggered his regeneration seconds later. (TV: The Curse of Fatal Death)

Eleventh Doctor's regeneration
After being shy by Emma's presence and believing the Master was a woman, the Eleventh Doctor began resuming his repairs on the Zectronic Beam Controller. He decided to examine another part of the Dalek ship to detect the problem, only to find that forgetting to unplug it first triggers another regeneration. (TV: The Curse of Fatal Death)

Twelfth Doctor's regeneration
After being hit with pure zectronic energy, the Twelfth Doctor was permanently killed as it stopped the regenerative process. However, his regeneration was eventually triggered, creating the female Thirteenth Doctor - with Emma theorising the reason was that the universe couldn't bare to be without the Doctor. (TV: The Curse of Fatal Death)

Other matters
The Eighth Doctor saw potential futures, one of which where he regenerated into this Ninth Doctor. (PROSE: The Tomorrow Windows)

The Twelfth Doctor’s final words before regeneration were “look after the universe for me, I've put a lot of work into it”. (TV: The Curse of Fatal Death) These exact words were uttered by another Twelfth Doctor when he believed he was to die. (WC: Prologue)