England's World Cup winners, former captains and most capped players have been invited to the country's 1,000th men's international against Montenegro.
November's Euro 2020 qualifier at Wembley will see the Three Lions become the first country to clock up 1,000 senior men's internationals, 147 years since the first against Scotland.
England are marking the occasion in a number of ways, including recognising the notable contributions of former internationals while the current crop will wear individual 'legacy numbers' on their shirts.
Southgate, who represented his country 57 times and has the legacy number 1,071, believes the November 14 qualifier will be an occasion to remember.
"It encapsulates the history and the importance of the team going back right the way through," the Three Lions boss said.
"We always talk to the players about the badge on the front of the shirt and how we are a small part of that history. 9️⃣9️⃣9️⃣ internationals1️⃣,2️⃣4️⃣4️⃣ playersThe #ThreeLions' legacy will be celebrated, but our journey continues 👊 Posted by England football team on Thursday, October 31, 2019
"There are so many players that have gone before and players that will come after.
"It's important we respect the shirt and leave it in a better place than when we found it, if you like.
"So, to be involved in this game is a particularly poignant moment, especially given that some of our great former players will be at the match as well."
England's 1966 World Cup winners have been invited to the Montenegro match, as have all former captains and players to have reached 50 caps. Viv Anderson, recognised as the first black professional footballer to represent England at senior level, will also be at the qualifier in recognition of his own notable role in the national team's history.
Football Association chairman Greg Clarke will present those in attendance with their own unique legacy number memento, while UEFA has granted special dispensation allowing the current players to have their numbers on display under the crest for the 1,000th game.
Southgate, who was presented with his own legacy number on a visit to an exhibition celebrating England's past at the National Football Museum in Manchester, said: "We didn't have that when I was playing, and I used to look at the cricket team with the number on the shirt.
"Again, it just makes you very proud that you see how few people have actually managed to achieve that and of course we always want to win and win trophies with England, but also it's about individual achievement.
"To become an England international is such a difficult and long journey for every player and for their families, for what it means to their family, their community, the school they went to, the boys' or youth club, Sunday team they played for.
"So, it is important sometimes to just take a step back and remember what that's about."
The legacy number will become a reference point long beyond the 1,000th game, but the digits will be moved into the inside of each collar after playing Montenegro – an occasion that offers the chance to wrap up Euro 2020 qualification.
"We've got to get the balance right for the team of enjoying this occasion and the build-up to a special game, but equally our job on the night is to qualify for a European Championship," Southgate said.
"That can lead to some more brilliant nights like we've had the chance to walk around and remind ourselves of today."
