Chalobah, 22, who was part of the Chelsea premier league title winning side last season, have signed for Watford on a five-year deal for an undisclosed fee.
“Nathaniel Chalobah has sealed a permanent return to Watford from Chelsea, the Hornets are delighted to confirm, Watford stated on their official website
The versatile was part of the England Under-21 side that reached the semi-finals of the European Championships in Poland last month.
In the 2012-13 seasons, Chalobah who is still eligible to play for Sierra Leone was on loan at Watford, making 42 appearances for the Hornets.
He has had spells with Nottingham Forest, Middlesbrough, Burnley, Reading and most recently in Italy with Napoli.
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