He suffered a fractured cheekbone, broken ankle and a black eye.
Police say a man in his 50s was assaulted by three men in West End, last Sunday (01/09)
They've now launched an appeal for witnesses and have released a description of the offenders.
The incident happened at around 12.10am and the victim needed hospital treatment afterwards.
The first offender is described as a white man, who was wearing a dark coloured hooded top.
The second is described as a white man, around 6ft tall with short dark hair. He was wearing a dark coloured tracksuit top and bottoms.
The third offender is described as a white man, who was wearing a grey coloured hooded top.
Detective Constable Samantha Bonner, based at Banbury police station, said: “This was a brutal, unprovoked attack that has left the victim with serious injuries.
“I am appealing for anyone who may have witnessed this incident or who may have information about what happened to please come forward."
Anyone with information can contact police on the non-emergency number 101, quoting reference 43190269540.