Taylor, 64, was the first head of state convicted by an international court since the Nazi trials after World War Two and the sentence set a precedent for the emerging system of international justice.
In an 11-year war that ended in 2002, Sierra Leone's Revolutionary United Front rebels murdered, raped and mutilated their way across Liberia's West African neighbor, helped by Taylor as he profited from a trade in so-called blood diamonds.
"He was found responsible for aiding and abetting some of the most heinous and brutal crimes in recorded history," said the Special Court for Sierra Leone's presiding judge Richard Lussick, emphazising that the world was "entering a new era of accountability."
Although shorter than the 80 years that prosecutors had sought, the sentence set a precedent for an international justice system aimed at deterring future war crimes. The court rejected all the defense's appeals for leniency.
"It is really significant that Taylor's status as a former head of state was taken as an aggravating factor as far as his sentence was concerned," said Geraldine Mattioli-Zeltner of Human Rights Watch.
Accused of genocide, Sudan's President Bashir is wanted by the International Criminal Court. The court is soon due to start the trial of Ivory Coast's ex-president, Laurent Gbagbo. President Assad does not currently face charges over the bloody suppression of an uprising.
Dressed in a blue suit and yellow tie, Taylor sat impassively through the roughly 45-minute sentencing.
Hands clasped in front of his mouth and his brow furrowed, Taylor shifted uneasily when the camera broadcasting proceedings settled on him.
The sentence was welcome for Edward Conteh, a Sierra Leonean whose left arm was hacked off by the rebels.
"Taylor is now 64 years old, I know that he cannot do 50 years in prison, so I'm satisfied," Conteh said in Freetown, scene of some of the bitterest fighting of the war.
Sierra Leone's average life expectancy dipped to 37 years during the war, in which an estimated 50,000 people were killed.
Lussick described some of the most hideous atrocities: the amputations of limbs which became a hallmark of the conflict, the gang rape victim whose eyes were torn out so she could not identify the perpetrators, the mother forced to carry a bag of human heads - including those of her children.
"She was forced to laugh while carrying the bag dripping with blood," he said. "She saw the heads of her children."
Taylor is due to serve his sentence at a high security prison in Britain.
In the Liberian capital Monrovia, the Taylor family spokesman called the trial a mockery of justice.
"They did this because America and Britain want to use our resources. Taylor did not yield to them for our oil. They had to do it to get our resources," Sando Johnson said.
Both sides are expected to appeal.