A nine-month-old baby and her mother were in the Kia Prince Philip crashed into when he overturned his Land Rover near Sandringham, police have confirmed.
The 97-year-old walked away unhurt but the two women in the other car required hospital treatment for a broken wrist and a cut knee. The baby was uninjured.
Eyewitness Roy Warne, 75, said the car had turned on its side “over and over” and the Duke of Edinburgh was bleeding after the crash.
“I saw a black car come out from a side road and it rolled and ended up on the other side of the road,” Roy Warne told BBC Radio 4’s Today Programme.
“There was a huge collision with another car, and I went to the other car and there was a baby in the back. With another man we got the baby out and then went to the black car to help.
“I realised then it the Duke of Edinburgh.”
Mr Warne confirmed Prince Philip was trapped in the car and had to be pulled from the wreckage.
“I asked him to move his left leg and that freed his right leg and then I helped him get out,” he added.
Norfolk Police said the 28-year-old driver suffered cuts to her knee while the passenger, a 45-year-old, broke her wrist.
Both were treated at Queen Elizabeth Hospital in King’s Lynn and have been discharged.
When questioned by Norfolk Police, the Duke of Edinburgh apparently blamed sun glare for the incident, Mr Warne claimed.
The crash happened at the Babingley crossroads on a stretch of the A149 which runs between the town of King’s Lynn and the north Norfolk coast.
It is a single carriageway and has a 60mph speed limit.
Witnesses told media the accident had occurred when Prince Philip was pulling out of a driveway onto a main road.
The road remained open and both the vehicles were recovered a short time after the crash.
There have been a total of 40 crashes, five of which have been fatal, on the A149 in the last six years.
A Buckingham Palace spokeswoman confirmed the duke was driving when the accident happened.
She added: “He saw a doctor as a precaution and the doctor confirmed he was not injured.”