Arsenal announced the signing of Germany midfielder Mesut Ozil from Real Madrid on this day in 2013 for a club-record fee of £43million.
Premier League rivals Manchester United also completed a major new signing on transfer deadline day, confirming a £27.5million deal to land Marouane Fellaini from Everton.
Ozil agreed a five-year deal and his fee comfortably surpassed Arsenal's previous transfer signing record of £15million, which they paid to Zenit St Petersburg for Andrey Arshavin in 2009.
The deal made Ozil the most expensive German footballer at the time and was a sign of the Gunners' intent on challenging for the Premier League title under former manager Arsene Wenger.
Ozil, who has made over 180 appearances for the north London club in all competitions, signed a new three-and-a-half-year deal in early 2018, but has yet to appear for them since top-flight football resumed in June.
Fellaini teamed back up with former Everton boss David Moyes when he made the switch to Old Trafford from Goodison Park. United confirmed the deal 51 minutes after the 11pm transfer deadline.
The Belgium international spent five and a half years at United and signed a new two-year deal in the summer of 2018, but was transferred to Chinese Super League club Shandong Luneng in February 2019.