The bodies of the two students were found at a bedsit in New Cross
A flat where two French students were murdered after a burglary went wrong was a scene of "almost unimaginable horror", the Old Bailey has heard.
Gabriel Ferez and Laurent Bonomo, both 23, suffered hundreds of stab wounds in the attack in Sterling Gardens in New Cross, south-east London, last June.
Prosecutor Crispin Aylett QC described the torture and murder as "inhuman".
Dano Sonnex, 23, of Peckham, south London, and Nigel Farmer, 33, of no fixed address, deny the murders.
Mr Aylett said: "To take revenge for the fact that they had been unable to steal money from Mr Ferez, both men were murdered in a way that can only be described as inhuman.
"What the firemen found was a scene of almost unimaginable horror."
Mr Aylett said the defendants burst into the bedsit at about 0530 BST on 29 June, overpowered and bound the two students and demanded their bank card numbers.
The students thought it best to co-operate but when one of their bank cards was retained by a cash machine the defendants wanted "revenge", jurors were told.
Mr Aylett said: "The two men, dressed only in their underpants, had been tied up.
"They had been bound at the ankles and the wrists. Their heads had been wrapped with towels.
"They had been subjected to an attack of brutal and sustained ferocity - one of them had been stabbed 194 times, the other 50 times.
"Both of them had been repeatedly stabbed in the head. In some instances, a knife had been used with such force that the skull had been penetrated and damage caused to the brain."
One of the burglars returned that night to set the flat on fire, the court heard.
The victims' badly-burnt bodies were found after an explosion at the property.
The biochemistry masters students from Polytech Clermont-Ferrand were weeks away from finishing a research project at Imperial College.
Jurors were told a neighbour alerted by the explosion had seen a man flee the property.
Both men deny murder, arson, false imprisonment and perverting justice
Mr Farmer, who was living with Mr Sonnex at the time, handed himself in days after an e-fit image was released.
The court heard Mr Sonnex's palm-mark was found on the frame of a foldaway bed and he was also seen on CCTV withdrawing money using one of the stolen bank cards.
The jury heard the two defendants were now blaming each other but Mr Aylett said the crime was a joint enterprise of "unmitigated evil".
Mr Sonnex enjoyed using "gratuitous violence" and had a previous conviction for inflicting grievous bodily harm with intent for a stabbing he carried out at the age of 16, the jury heard.
In a robbery last year, he had allegedly tied up his pregnant foster sister and her boyfriend, jurors were told.
The court was also told Mr Farmer was a drug addict who had checked into a psychiatric hospital in Woolwich a month before the murders but left after four days, complaining about not getting the "right help".
Mr Farmer and Mr Sonnex deny murder, arson, false imprisonment and trying to pervert the course of justice.
Mr Sonnex has admitted one count of burglary at the property on the same date as the murders. Mr Farmer denies a charge of burglary.
The trial was adjourned until Tuesday.