A Polish teenager was stabbed to death outside a Tube station by a man who blamed his country for the Second World War, a court has heard.
Marcin Bilaszewski, 19, was knifed in the back by Dutch national Alphonse Kruizinga during a night out to celebrate his girlfriend's 18th birthday on May 8 last year, a jury was told.
Kruizinga, 34, of no fixed address, denies murder and two knife charges.
On the night he was killed, Mr Bilaszewski had been with his girlfriend Anna Betlinska and a group of friends, said Roger Smart, prosecuting.
Kruizinga had followed them from Clapton Common, east London, on to a bus as they were making their way to a party, despite being told he was not welcome, the jury at the Old Bailey was told.
Mr Smart said he had been making comments to them "of an extremely strange and offensive nature", and told the court: "For example, on the way to the bus stop he began to say that it was the fault of the Polish that the Second World War had occurred."
Mr Smart said Kruizinga "was effectively stalking the group" and followed them as they got off the bus at Finsbury Park, when Miss Betlinska became "outraged" at his behaviour and got into a fight with him.
"Mr Bilaszewski also became involved. He was not armed. Alphonse Kruizinga then produced a knife from his sleeve or pocket and in a swinging motion stabbed the deceased to his lower back," Mr Smart said.
Miss Betlinska chased off the knifeman and the victim was taken to hospital where he later died, the jury was told.