Lee Johnson has been sacked by Hibernian after five defeats in nine games this season.
Johnson's backroom team members Jamie McAllister and Adam Owen have also departed Easter Road and former captain David Gray becomes caretaker boss.
Hibs, beaten 3-2 at home by Livingston on Saturday, have lost their opening three Scottish Premiership matches.
They were humbled 5-0 by visitors Aston Villa in Wednesday's Europa Conference League play-off first leg.
Chief executive Ben Kensell said: "The club has taken the tough decision to relieve Lee Johnson of his duties following a disappointing start to the domestic campaign.
"We wish Lee and his coaching staff all the best for the future and thank them for their efforts.
"David Gray will take charge of the first team as caretaker manager for the immediate future, and be supported by Stuart Garden. No further comment will be made at this time."
Former Oldham, Barnsley, Bristol City and Sunderland boss Johnson took over from Shaun Maloney in May 2022 and Hibs finished fifth in his first season in charge.
After Premiership winners Celtic also won the Scottish Cup, that fifth place was enough to secure a Conference League qualifying berth for Hibs.
They opened their season with a 2-1 defeat away to Andorra's Inter d'Escales but recovered with a 6-1 home win and defeated Swiss side Luzern 5-3 on aggregate to set up the Villa tie.
However, a 3-2 loss at home to St Mirren, a 2-1 defeat at Motherwell and the thrashing at the hands of Villa increased the pressure on 42-year-old Johnson going into Saturday's visit of Livi.
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