Jan Siewert's appointment as David Wagner's successor at Huddersfield means the 36-year-old has become the youngest manager in the Premier League.
Here, Press Association Sport looks at five similarly youthful figures who may provide an indicator of how he will fare.
Chris Coleman
The Welshman was only 32 when, in May 2003, he was appointed as Fulham's permanent successor to the experienced Jean Tigana, having led them to victory in three of his five fixtures as caretaker manager. In his first full season, until the departure of Louis Saha to Manchester United, they were impressively on course to challenge for qualification to the Champions League, but by the point of his sacking in April 2007 they were battling to avoid relegation.
Andre Villas-Boas
Considered one of Europe's rising managerial talents having excelled at Porto, who he had just inspired to the Portuguese league title, League Cup and Europa League, Villas-Boas was 33 when Chelsea recruited him – he was the same age as senior players Frank Lampard and Didier Drogba. Chelsea went on to win the FA Cup and Champions League, but under Roberto Di Matteo having sacked Villas-Boas in March 2012, nine months into his difficult reign there.
Paul Jewell
The then-Bradford manager was just 34 when he was thrust into the stresses of a Premier League relegation battle, something Siewert will soon know all about. Having performed admirably all season – an entertaining 5-4 defeat at West Ham was one highlight – his team went to Champions League qualification-chasing Liverpool on the season's final day, and remarkably oversaw a 1-0 victory that secured an even unlikelier second season of top-flight football. He left for Sheffield Wednesday that summer, and while Bradford then struggled and were relegated, beyond a successful period at Wigan, his reputation has similarly not recovered.
Gareth Southgate
The reigning England manager succeeded the then-England manager, Steve McClaren, when he was appointed by Middlesbrough aged 35 in June 2006. He lasted until October 2009, when he was sacked in what their chairman Steve Gibson described as "the hardest decision I've had to make in football", having had a mixed period in charge which concluded with them fourth in the Championship following relegation that summer. Significant budget cuts at the club are widely considered to have influenced his time there.
Roy Keane
The former Manchester United captain was 36 when Sunderland began their only full season in the Premier League with him in charge. He had already excelled in leading them to promotion following a traumatic relegation and start to the previous Championship season before his arrival, and impressed again in ensuring they survived that first season back. Having spent heavily the following summer, he then began to struggle to maintain their progress, and left in December 2008.
