McClaren arrived at the FA headquarters in London around 3.30am after travelling from his North Yorkshire home. He completed the formalities with the FA's selection panel and was unveiled to the media just after 4.30pm.
He has signed a four year deal and will replace Sven Goran Eriksson after the World Cup on 1st August, but first he must complete the league season with Boro and take his team to the UEFA Cup Final in Eindhoven next Wednesday.