Of all Liverpool's transfer dealings under Jurgen Klopp, it was perhaps the most significant.
Even if, at the time, it wasn't met with universal acclaim among Reds supporters.
The £35million handed over for Alex Oxlade-Chamberlain last August left many scratching their heads. Why spend so much on someone who wasn't a regular for his club?
Oxlade-Chamberlain soon ended that debate with his performances during an excellent 2018 devastatingly curtailed by the serious knee injury suffered against Roma in April.
But it wasn't the player himself that was could prove the most influential aspect of that deal.
Instead, it's where he came from. Arsenal. One of Liverpool's supposed rivals.
Matters over the subsequent campaign underlined that while the Gunners stagnated to the point of Arsene Wenger ending his 22-year tenure in the hotseat, Liverpool moved on and reached the Champions League final.
It was the right move. And in doing so, it broke down a sizeable barrier.
Liverpool is now a destination for all leading talent, including those on the books of their nearest Premier League challengers.
That was brought into sharp focus on Thursday when it emerged Manchester United forward Anthony Martial wants out at Old Trafford.
“After thinking about all the possibilities and scenarios, Anthony wants to leave Manchester United,” said his agent, Philippe Lamboley.
“Manchester United want to extend Anthony’s contract and do not want him to leave, but we have not been able to find an agreement for several months.
When does the season kick off?
Jurgen Klopp looks on as his team warm up prior to the UEFA Champions League Final between Real Madrid and Liverpool at NSC Olimpiyskiy Stadium on May 26, 2018 in Kiev, Ukraine.
Jurgen Klopp and Mauricio Pochettino Hotspur exchange words prior to kick off during the Premier League match between Tottenham Hotspur and Liverpool at White Hart Lane on August 27, 2016 in London, England.
“I think that when Manchester United, which is the most powerful club in the world it must be remembered, do not find an agreement in eight months of negotiations, it is because they do not really want to make him an important member of the team. That’s the root of this decision.”
United swiftly moved to let it be known Martial was going nowhere, with the threat likely to merely be provoking a kick up the backside regarding contract discussions.
But it did briefly prompt a debate over whether Liverpool could make a cheeky offer for the Frenchman's services.
Such a topic has already been discussed regarding Real Madrid, where the likes of Gareth Bale and Marco Asensio face futures made increasingly uncertain by the arrival of Julen Lopetegui as manager at the Bernabeu.
Liverpool are in a position of strength, their stock higher than at any time in the last decade or so.
Why not a nibble at Brazil international Willian, who hasn't been a regular at Chelsea? Agent Roberto Firmino could do the persuading at the World Cup.
Then there's Tottenham Hotspur centre-back Toby Alderweireld, potentially seeking pastures new.
And with suggestions Manchester City have yet to agree a new contract with Raheem Sterling, the opportunity is there to test the waters for a sensational return to Anfield.
It's up to Klopp and his recruitment team. If they want to, it could happen.
The departure of Sterling, following earlier exits of Fernando Torres and Luis Suarez, highlighted Liverpool as primarily a selling club to their main rivals. The route was one-way.
Nothing is off the table now. That last 12 months has seen to that.