The assault happened on North Street at around half past midnight in the early hours of Saturday, May 29.
The victim, a 66-year-old man, was seriously injured and taken to hospital.
Police are now appealing for a key witness who they believe saw part, or all of the assault.
Officers are appealing for a woman with blonde hair to come forward, who can be seen on CCTV from behind in the vicinity of the attack.
Police are urging the woman to get in touch by calling North Yorkshire Police on 101, select option 2, and ask for Detective Constable Amy McDougall 582. You can also email [email protected]
Information can be passed on anonymously to Crimestoppers on 0800 555 111.
Quote the North Yorkshire Police reference number: 12210127488.
A 21-year-old man was arrested in connection with the incident, he was charged with wounding with intent and was due to appear in court on Monday, May 31.