An aristocrat who admitted three driving charges including a road rage attack on another motorist's car has been jailed for six months.
The Marquess of Blandford is being treated at the Priory Hospital
The Marquess of Blandford, Charles Spencer-Churchill, was jailed on charges of dangerous driving, careless driving and causing criminal damage.
He admitted the offences at an earlier hearing at Oxford Crown Court.
The Duke of Marlborough's son, commonly known as Jamie Blandford, is currently being treated at the Priory Hospital.
The court heard how the marquess, aged 51, of Wootton Downs, Oxford, had "retreated into a life of drugs".
His doctor at the hospital in London had said his progress would be "undermined" by a custodial sentence.
But Judge David Morton Jack said: "There cannot be one standard for the unhappy and another for those settled in life.
"Driving like yours is decidedly criminal. You are completely responsible and completely culpable for your driving.
"It is perhaps a partial explanation, but it is no mitigation to say at the time of the driving you were under personal stress.
"Your driving was deliberate and the very word danger informs of the potential for injury."
At the time of the offences Blandford was battling with a number of personal crises, including a split from his wife and a relapse into drug taking, the court heard.
Rachel Drake, prosecuting, said the first offence took place on the M42 motorway on 16 June last year, when a police patrol spotted his Range Rover Sport on the northbound carriageway.
The court was shown video footage from inside the police car which showed the Range Rover weaving in and out of traffic without indicating before pulling on to a slip road.
The police car reached speeds of 95mph to catch up with the marquess.
The second offence took place on the A4095 in Oxfordshire on 22 August last year, when motorist Graeme Kennedy was driving towards Witney.
Ms Drake said: "[Mr Kennedy] was overtaken when the Range Rover cut in front of him and caused him to brake sharply.
"Mr Kennedy beeped his horn so the driver was aware that he viewed the manoeuvre as inappropriate.
Mounted grass verge
"The Range Rover slammed on its brakes, practically coming to a halt, and he had to swerve out to avoid an accident."
The court heard that the Range Rover then "mounted a grass verge to overtake again before coming to an abrupt halt".
The defendant got out and approached Mr Kennedy's car, swearing and shouting: "Who do you think you are, beeping your horn at me?"
Ms Drake said: "Mr Kennedy reversed his vehicle and pulled away and as he did that, the defendant kicked the side of his door."
Judge Morton Jack ordered Blandford to pay £2,577 costs and pass an extended driving test when his three-and-a-half year disqualification ends.
The judge said he accepted that drink or drugs had not played any part in the offences.