A man armed with a large knife broke into the house of George Harrison, the former Beatle, early this morning and stabbed him in the chest, the authorities said, and evidence emerged that the assailant may have harbored a dangerous obsession with the band.

Mr. Harrison, 56, one of three remaining members of the Beatles after the murder of John Lennon by a crazed fan 19 years ago, was treated for a collapsed lung and various minor stab wounds at a hospital near his home in Henley-on-Thames. He was listed in stable condition tonight, and doctors said that his wounds were not life-threatening.

His wife, Olivia, was treated for cuts and bruises she had suffered in the struggle with the intruder and released.

The police said they had arrested a 33-year-old man from Liverpool, the hometown of all four Beatles, on suspicion of attempted murder. In keeping with standard British practice, the police would not release the suspect's name or give details about the investigation. But they did say that it was possible it was a deliberate attack, rather than a simple break-in.