Billy West, 20, saw red after Clive Merrifield, 44, complained about West's baby's incessant crying in an Indian restaurant in Islington, North London.
The baby had been crying at the table for half an hour when Mr Merrifield approached West, his girlfriend and their dining companion and suggested that as it was after 10pm, the baby might be tired.
The mother held the tot up and sneered: 'It's a baby' in reply. West and his companion then offered to settle the matter 'outside' with Mr Merrifield. West and his family were then escorted from the premises by staff, but he returned alone five minutes later, pulled a bottle of wine from Mr Merrifield's ice bucket and smashed it over his head.
Mr Merrifield was left with a four-inch wound to his head which required 16 stitches.
The former police constable who now runs an auditing business told reporters:
"The child had been crying and crying at the next table, it was constant. The mother kept getting up to hold it up to the mirror behind us, but it wouldn't stop. It was very loud – other people noticed but they didn't say anything, and after about half an hour I just said to my girlfriend: 'I've had enough'."
"I went over and said very politely that I was sorry but this is a quiet restaurant and we're trying to enjoy our meal and your baby won't stop crying. I asked if they could take it outside for a bit, and said it might be tired at this time of night. She just held it up and started shaking it and saying 'It's a baby'. They asked me if I had a problem with children, which I don't, and the two men told me we could 'sort this out outside'."
"The staff asked them to leave and we carried on eating. The next thing I knew I had been whacked on the back of the head. He had hit me with my bottle of wine. I just remember seeing my girlfriend's face, looking really worried, and the blood and glass on her top. I got up but he had gone, and I looked down and saw my shirt soaked in blood."
The court heard West has previous convictions for assault, and was on a suspended sentence for aggravated vehicle taking when he attacked Clive Merrifield.
Have you ever complained about a child's crying - or would you be too worried about the parents' response?