Children who take their parents to court are in the news. One is taking his step-father to the European Courts to seek a ban on parental caning. Another has had his father bound over to keep the peace for a year, after receiving a slapping. For me, what marks these cases out is the apparent breach in a code as fundamental to British family culture as to any Mafia: never betray the family.

As head of a big urban comprehensive I was frustrated by the stoical silence of children protecting violent and abusive parents. The poorer the family and the more desperate the home, the more defiantly loyal was the victim. I always thought it was fear and self-preservation that prompted this response. Then a powerful incident convinced me that the code was a more profound lifeline than I had suspected.

We had a split site school separated by a busy road which I crossed about 10 times each day. One afternoon I noticed a scruffy, long-haired bloke in his 30s hovering near the school gates. He was still there an hour later, but it was not abnormal for weirdos to gather there. He lurched up to me and demanded to take his son out of school at once. He hadn’t seen him for a couple of months ”‘cos he’d been workin’ on the oil rigs”. His eyes were blank and he looked and smelled as though he was living rough.

I invited him to come with me into school but he refused. He said that if I didn’t bring his son, Wayne, he would wait for him at the gate and take him to his own place. This, he informed me, was a nearby squat - he didn’t live with Wayne’s mother any more.

I went inside and phoned the mother who said her husband had just been released from prison after serving three years for drugs offences and violence. She said it was up to Wayne to decide what to do. She didn’t care whether they met or not, but she didn’t want the boy going to the squat.

I sent for Wayne. He came in looking wary, flicking his long straight hair out of blue eyes as sharp and alert as his father’s had been vacant. He was a wild boy - like an electric eel, brilliant at football and prone to explosive violence. I had coached his soccer team so he knew I wasn’t all bad.

I explained the situation and he considered the options, including a car home via another exit. He turned this down and opted for a chat with his dad.

As nearly 2,000 youngsters swarmed out of classes to head for home, I led the way into my office where Wayne was swivelling uneasily in the chair behind my desk. I showed his father to an armchair and turned to hand him a mug of tea. Before I could, Wayne shot across the room and threw his arms around his filthy, derelict father. They hugged each other for minutes in silence except for two long, deep, hopeless sobs from Wayne.

As I left the room I saw Wayne brush lice from his father’s forehead with a calm, caring, almost paternal hand. They talked for about an hour. Then the door opened and the father left without a word. Wayne shuffled out awkwardly, grabbed his skateboard, and joined his cronies who’d waited patiently, sprawled on the pavement beyond the gates.

The father died soon afterwards. Over the next few years, Wayne should have been expelled about 20 times but wasn’t. Once, when I was reading the riot act, he said with a wry grin: “You know, if you rant on like this, I’ll have to get my dad to come and sort you out!” It was a good joke, and we both laughed. But it gave me insight into the code which sustained so many fractured families.

It was based, not just on fear or loyalty, but on the deep and abiding yearning of young people to have parents who loved them, with even one-tenth of the love that they offered in a short lifetime of disappointments. Only one dream would do. If that has really gone, we need something very good to put in its place.

Michael Conway writes under a pseudonym but was a head and deputy in Brighton, East Sussex for over 20 years.