World Cup tales part 4: Zinedine Zidane's infamous headbutt and why he did it in 2006 final

All these years on, it remains one of the most shocking moments ever witnessed on a football pitch.

Yet while the headbutt itself is remembered around the world, the reasons behind it are often forgotten.

The incident occurred during the 2006 World Cup final between France and Italy in Berlin.

For Zidane, it was supposed to be the perfect farewell.

The French captain had announced before the tournament that he would retire after the competition. Despite being 34 years old, he rolled back the years in Germany, inspiring France to the final with a series of superb performances.

Against Brazil in the quarter-finals, he produced one of the finest displays of his career. He then helped France overcome Portugal to set up a showdown with Italy.

The final started brilliantly for Zidane.

After just seven minutes, France were awarded a penalty when Florent Malouda was fouled inside the area.

Zidane stepped up and coolly chipped the ball down the middle of the goal, with his audacious Panenka effort clipping the underside of the crossbar before crossing the line.

Italy responded through Materazzi, who powered home a header from a corner to level the match. With neither side able to find a winner, the final drifted into extra time.

Then came the moment that changed everything.

With just minutes remaining, television cameras suddenly showed Materazzi lying on the turf. Players from both teams gathered around as confusion spread throughout Berlin's Olympiastadion.

The reason soon became clear.

After an exchange of words between the two players, Zidane had turned and driven his head into Materazzi's chest.

Initially, referee Horacio Elizondo did not appear to see the incident.

However, after consulting his assistants, the Argentine official produced a straight red card. Zidane's World Cup career, as a result, was over.

As he walked past the trophy on his way down the tunnel, one of football's most iconic images was created.

Italy eventually won the final 5-3 on penalties after a 1-1 draw.

The immediate aftermath was filled with speculation.

What could possibly have caused one of the calmest and most gifted players in football history to lose his temper on the biggest stage of all?

For several days, neither Zidane nor Materazzi revealed exactly what had been said. Rumours, in turn, spread around the world.

Some claimed insults had been directed at Zidane's mother. Others suggested comments had been made about his family. The uncertainty only added to the intrigue surrounding the incident.

Eventually, both men provided their versions of events.

Materazzi admitted there had been verbal exchanges between the pair but denied insulting Zidane's mother. Instead, the Italian later said the comments related to Zidane's sister.

Zidane subsequently confirmed that remarks about members of his family had provoked his reaction.

Speaking after the tournament, the Frenchman said he could not accept what had been said and acknowledged that the headbutt was wrong, while insisting the comments had deeply offended him.

"I apologise, but there was a reason for it," Zidane said.

The exact words exchanged have never been independently verified, meaning only Zidane and Materazzi know precisely what was said on the pitch that night.

What is certain is that the incident transformed the legacy of the final.

Instead of being remembered solely for his brilliance throughout the tournament, Zidane's final appearance became forever linked to a moment of extraordinary controversy.

Remarkably, his performances in Germany were still recognised.

Despite being sent off in the final, Zidane won the Golden Ball award as the best player of the tournament after helping France reach the showpiece event.

For Materazzi, the night was equally unforgettable.

The defender scored Italy's goal, played a key role in the dramatic finale and became permanently associated with one of football's most famous flashpoints.

Twenty years later, the headbutt remains one of the defining images in World Cup history.

It marked the end of a legendary career, denied France the presence of their captain during the penalty shootout and ensured the 2006 final would be remembered for far more than the result. As football moments go, few have generated more debate.