Bruce, the former Manchester United defender, takes charge of his boyhood club after leaving his job at second-tier Sheffield Wednesday. He is the 10th permanent manager under Ashley's troubled ownership that began in 2007.
It is being widely viewed as an uninspiring appointment, with the 58-year-old Bruce having been relegated twice from the Premier League — with Birmingham in 2006 and Hull in 2015. He has a win percentage in the top flight of 28%, though has experience of managing more than 900 competitive matches in a 21-year coaching career.
"There is a huge challenge ahead of us," said Bruce, who has signed a three-year deal, "but it's one that my staff and I are ready for. We'll roll our sleeves up and we'll be giving it everything from the off to ensure supporters have a successful team that they can be proud of."
Yet Newcastle supporters are still angry that Ashley didn't reach an agreement to extend the contract of Benitez, who left last month after more than 3½ years in charge saying the club "did not share his vision." Benitez has since taken over at Chinese Super League side Dalian Yifang.
Benitez couldn't stop Newcastle being relegated when he joined in March 2016, but helped the team immediately bounce back into the Premier League the following season. Finishing 10th and 13th in the last two seasons cemented Newcastle's place in the top flight.
Bruce could face a tough first season because Newcastle will not have its two starting strikers from last season, Salomon Rondon and Ayoze Perez. Rondon, who was only on loan from West Bromwich Albion, hasn't been signed on a full-time deal, while Perez has moved to Leicester.
Bruce and his staff are due to fly out to meet up with Newcastle's players in China, where the team is playing in a pre-season tournament. Sheffield Wednesday said it was "disappointed to learn via (a) public statement issued by Newcastle" that Bruce and his staff had been hired, and that there remained "outstanding legal issues to be resolved."
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