Locked-in syndrome sufferer Tony Nicklinson left a final poignant message before dying peacefully at home surrounded by his family.
He said: "Goodbye world the time has come, I had some fun."
Mr Nicklinson, 58, died six days after he lost a landmark High Court right-to-die action in which he warned that he was condemned to a life of "pure torture".
He was left paralysed by a catastrophic stroke while on a business trip to Athens in 2005. His family said that after receiving a draft of the judgment "the fight seemed to go out of him".
And in the past few days the father-of-two suffered rapidly deteriorating health when he contracted pneumonia and refused food.
When Mr Nicklinson died on Wednesday morning at his home in Melksham, Wiltshire, his wife Jane and daughters Lauren and Beth, and sister Ginny were by his side.
A message posted on Mr Nicklinson's Twitter profile said: "You may already know, my Dad died peacefully this morning of natural causes. He was 58." Mrs Nicklinson tweeted: "I have lost the love of my life, but he suffers no more."
Daughter Beth posted on the social networking site: "RIP @TonyNicklinson. Couldn't have asked for a better dad, so strong. You are now at peace, we will be fine. I love you xxx." Her sister Lauren added: "Dad, you are finally at peace. Beth and I are so proud to be your daughters, we got our strength from you. I love you xxx"
Wiltshire Police said there were no suspicious circumstances.
Mr Nicklinson's lawyer, Saimo Chahal of Bindmans LLP, said he had been heartbroken at the ruling and told her: "So, we lost. In truth I am crestfallen, totally devastated and very frightened. I fear for the future and the misery it is bound to bring."