Mr Stringer said he was then horrified to see four other men on the other side of a hedge urging their companion with phrases such as: 'Go on my ******, slog him.'
He said: 'I had no strength left, I only had my voice and I tried to find the most shocking words to shout, thinking that if they came through that hedge we could be killed. There was nobody there to save us, we were alone.
'Using their own words, I shouted 'and if you ******s come into my garden I will ****ing hit you with this'. I merely flung their own words back at them. I am not racist.'
The other men retreated to their cars by the gate, where they stood holding a crossbow, claimed Mr Stringer.
Moments before police arrived, the remaining intruder made a 999 call saying he had been attacked by two men, suffered numerous injuries and racially abused.
Five police cars then arrived and officers arrested Mr Stringer and his son on suspicion of a racially aggravated attack. Police briefly questioned the men at the gate but none was arrested.
Mr Stringer was enjoying a Sunday afternoon with his wife and three children aged 26, 24 and 22 at their £2million, 40-room home in Morningthorpe, near Norwich, when three cars pulled up at the gates and a group of men climbed into the grounds.
He rang 999. 'I told the operator we were under attack,' he said. 'I could see at least three men running between the trees. One had a weapon which looked like a crossbow. The others had steel bars.'
When a fourth man armed with what appeared to be a handgun started banging on their glass front door, Mr Stringer said he was compelled to act. He grabbed a child's hockey stick and confronted the intruder.
'My son told me he had seen a gun,' he said. 'I went outside and I kept shouting loudly at him to leave and that the police were on the way.
'I used my hands and the stick to push him away from the house. He kept punching and kicking me. I was by that time bruised, bleeding and utterly exhausted.'
He said police were uninterested in the injuries he suffered and told him the gang had simply entered his garden as civil trespassers and 'done nothing wrong'. Mr Stringer said he later discovered a discarded metal bar and three knives.
Within weeks he was informed that police had closed the file about the trespass.
Now, six months on, he has had to resign as a Norwich magistrate as he would have been unable to launch a private prosecution while sitting on the bench.
