Barnet manager Martin Allen has left the club to take over at Second Division Brentford.
Allen has left Underhill
Allen, 38, took charge at Underhill a year ago in his first full managerial role and has guided Barnet to fifth place in the Conference table.
He will succeed Wally Downes at Griffin Park, who was sacked this week.
"Martin's enthusiastic and knows our players. He knows the area and his goals are the same as ours," said Bees director John McGlashan.
"He had all the right qualifications and has done his apprenticeship coaching
at Reading," added McGlashan.
Barnet have put coach Adrian Whitbread and physio Damien Doyle in temporary charge for Saturday's game with Conference leaders Chester.
Allen said goodbye to the squad on Thursday morning after completing his move to Griffin Park.
A Barnet spokesman said: "It is obviously premature to ask if we have anyone lined up to take over - although we have had a series of calls already.
"It's also unhelpful to read wild speculation that players are leaving."