Europe's problems nearly always start with miscommunication: the Ems telegram and the Zidane headbutt being just two examples.

BBC: The Sarko smackdown!

Previous surveys for the charity have suggested many pupils are bad sports, willing to elbow, headbutt and argue their way to victory.

BBC: Pupils being bullied on sports fields, survey says

"When their heads come in I probably need to duck mine down a bit so they won't headbutt me in the face, " he said.

BBC: Gavin prepared for rough tactics

United had Nani red carded for a headbutt on Hammers defender Lucas Neill but rarely looked like dropping points in their last home game of the season.

BBC: Ferguson piles stress on Chelsea

The court heard from two police officers who told the court they were on hand when the incident happened and they clearly saw Lennon headbutt Mr McKee.

BBC: EDL leader Stephen Lennon convicted of assault

In May's EPL finale, Barton was sent off for elbowing Carlos Tevez, then kicking the striker's fellow Argentine Sergio Aguero before appearing to aim a headbutt at City captain Vincent Kompany.

CNN: Barton's English ban to apply in France

The Milan midfielder will miss the Spurs game due to a four-match European for his headbutt on Spurs assistant boss Joe Jordan in the first leg which the Rossoneri lost 1-0.

BBC: Barcelona beat Zaragoza as AC Milan edge past Juventus

McLeish cited an incident in his side's 1-1 draw with Tottenham on 4 December in which Spurs defender Alan Hutton appeared to headbutt the Blues' David Murphy, but was not charged.

BBC: Birmingham's Lee Bowyer receives three-match ban

Materazzi is still best known for his antics in the 2006 World Cup final, when his comments to Zinedine Zidane led to the France playmaker being sent off for a vicious headbutt in his farewell international which ended with the Italians being crowned world champions.

CNN: Veteran Materazzi handed new Inter deal