A man who beat up his partner in front of their six-year-old son has been told by a judge his attack was the worst case of domestic violence he had heard.
Norwich Crown Court heard Derek D'eath, 26, of Harewood Road, Norwich, admitted grievous bodily harm in February.
His partner, Sarah Norton, suffered eight stab wounds, severe facial bruising, and a broken finger.
Judge Peter Jacobs jailed D'eath, who had a drug problem and has an attention deficit disorder, for 21 months.
The court was told the attack only ended when the child entered the room and it was reported to the police by Miss Norton's father.
The boy was the eldest of the couple's three children and was so traumatised by witnessing the attack he is still receiving counselling from Norfolk Social Services, the court heard.
A medical expert said the injuries Miss Norton had suffered were the worst he had seen in his four years as a consultant and in 10 years as a doctor.
William Carter, defending, said D'eath accepted what he did and pleaded guilty.
Judge Jacobs said: "Courts take domestic violence very seriously and I would be failing in my duty if I do not send you to prison.
"She suffered really serious facial bruising. This is the worst case I have ever seen."