Shortly before 10am on Monday (August 30), Northumbria Police received a report of a collision involving a blue Citroen C3 and a blue MG ZS on the A1068, between Alnwick and Lesbury.
Officers from the Force's motor patrols department attended the scene alongside paramedics.
The 33-year-old male driver of the Citroen and his 29-year-old female passenger were taken to hospital by air ambulance.
The occupants of the second car received treatment at the scene.
Sadly, the male driver of the Citroen died as a result of his injuries on Tuesday.
He can now be named as Joe Spedding of Newcastle.
His family are being supported by specialist family liaison officers.
In a joint statement, his family said: "We are incredibly sad and would like privacy at this time.”
Northumbria Police are continuing to investigate and gather information about the nature of the incident and have appealed for members of the public who witnessed it or drivers with dash cam footage to get in touch.
Sergeant Dave Roberts, of Northumbria Police's motor patrols department, said: “This was a serious collision which has devastatingly resulted in a man losing his life aged just 33.
“Our thoughts are with Joe’s family and loved ones, who are being offered supported by officers as they try to come to terms with what has happened.
He added: “We immediately launched an investigation following this incident and we are gathering information to build up a picture of how the collision occurred.
“We are appealing for anyone who witnessed the collision or may have dash cam footage and has not yet come forward to get in touch immediately.”
Sgt Roberts added: “Any information, no matter how small or insignificant you may fear it is, could prove crucial to this investigation so please do get in touch.”
The female passenger of the Citroen remains in hospital with serious injuries.
Anyone with information, or dashcam footage is asked to contact 101, or use the Tell us Something page on Northumbria Police’s website, quoting log NP-20210830-0326.