It shocked the football world, more than doubling the existing world record-transfer fee and left Barcelona in transfer disarray as they frantically tried to replace him in the last three weeks of the summer window.
Their rivals weren't unaffected either. They realised that European clubs' riches could lead to them being caught unawares in future and, in the following eight weeks, signed several of their top stars to new deals that include astronomical release clauses.
During September, the Blancos signed Isco, Marcelo, Dani Carvajal, Karim Benzema, Marcos Llorente, Raphael Varane and Marco Asensio to new deals.
Asensio was the most recent to pen fresh terms, as he inked a contract through 2023 on Thursday.
With those new contracts came buyout clauses that are designed to turn back even Europe's most extravagant spenders.
Benzema's release clause was set at an eye-watering €1 billion, with Isco and Asensio at €700m each, Carvajal at €350m, and Varane, Marcelo and Llorente all at €200m.
All seven players are now tied to Madrid through at least 2021 and with their release clauses set, they all appear destined to stay at the Bernabeu for the long haul.
|PLAYER||BUYOUT CLAUSE||CONTRACT EXPIRES|
|Karim Benzema||€1 billion||2021|
Meanwhile at Camp Nou, Barcelona are still waiting for Lionel Messi to put pen to paper on his new contract, which has been verbally agreed but not signed.
Messi's buyout clause on his existing contract is €300m, far less than many of his Santiago Bernabeu rivals and potentially exposing him to a January bid from a Champions League rival.