However, he led his country to a first World Cup semi-final in 28 years in his first tournament in charge three years ago in Russia and has now gone where no England manager has before at the European Championship.
AFP Sport looks at how the 50-year-old took England from the embarrassment of the Allardyce scandal to the brink of European champions.
Courage of his convictions
For decades England managers have bowed to the will of media and fans to cram the most talented individuals into the starting line-up, even at the expense of the overall structure of the team.
Paul Scholes retired from international football after years of being stuck out of position on the left wing to make room for Frank Lampard and Steven Gerrard as a “golden generation” failed to progress beyond the quarter-finals of major tournaments under Sven-Goran Eriksson in 2002, 2004 and 2006.
By contrast, Southgate has been happy to leave an abundance of attacking talent on the bench.
With captain Harry Kane and Raheem Sterling his tried and trusted duo up front, there has been only one place in the team for Bukayo Saka, Jack Grealish, Phil Foden, Jadon Sancho and Marcus Rashford to battle for.
A crowd favourite, substitute Grealish even had to suffer the ignominy of being replaced after just 36 minutes of action as England made adjustments to see out their extra-time victory over Denmark in the semi-finals.
“There is a nasty side to Gareth and he was spot-on to do that,” said former England captain Alan Shearer.
Southgate’s solid defensive structure, with West Ham’s Declan Rice and Kalvin Phillips of Leeds forming a powerful midfield axis, has meant England have conceded just once in six games at Euro 2020.
The esteem in which Southgate is held by his counterparts was shown when Denmark boss Kasper Hjulmand began his post-match press conference with an effusive tribute.
“I followed what the FA has done strategically and especially how Gareth has led this team for a number of years now,” said Hjulmand. “How he represents and communicates is outstanding. Congratulations Gareth, I think you are doing a great job in a difficult job.”
Southgate has been the perfect leader for a squad with a social conscience, not content to let their football do the talking.
Under his reign, England players have had to cope with racial abuse in Montenegro and Bulgaria.
They began the tournament being booed by sections of their own fans for taking the knee as a protest against racial injustice.
“The most important thing for our players is to know we are totally united on it, we are totally committed to supporting each other,” Southgate said at the time, standing up to complaints from leading politicians about “gesture politics”.
Southgate’s tactical nous has consistently been questioned, but he has shown a willingness to adapt to what is required to win.
In Russia three years ago, the switch to a back five protected an inexperienced goalkeeper and defence.
This time he has used a 4-3-3 to get an extra attacking player into the side, other than the last-16 tie against Germany, where a change of formation nullified the threat posed by wing-backs Joshua Kimmich and Robin Gosens.
Saka justified his start against Denmark by setting up England’s equaliser as Simon Kjaer turned the ball into his own net.
But after Grealish was introduced, Sterling switched from the left wing to the right, where he won the decisive -- albeit contentious -- penalty to end England’s long wait to reach a final.