Date of birth
Marquis joined the Blues from Doncaster ahead of the 2019/20 season.
The striker – who had a short loan spell at Fratton Park in 2013 – began his career with Millwall and was handed his professional debut by Kenny Jackett Jackett at Bristol Rovers in 2009.
He had several stints out on loan, including a two-month stay at Pompey in the first half of the 2013/14 campaign.
Marquis netted two goals in six appearances, grabbing a consolation in a 4-2 defeat at York and then scoring in an EFL Trophy win at Oxford.
He signed for Doncaster in the summer of 2016 and struck 67 times in 153 appearances during three years in south Yorkshire.
Twenty-six of those goals arrived in the 2018/19 campaign, as Rovers suffered a penalty shoot-out defeat to Charlton in the League One play-offs.
A prolific spell for Pompey last term saw Marquis collect the 'PFA League One Player of the Month' award.