It is not often that a player will move from one traditional "big six" club to another but following the transfer of Jorginho from Chelsea to Arsenal, we're taking a look at some of the players who switched between west and north London and vice-versa in the Premier League era.
Ashley Cole (Arsenal to Chelsea, 2006)
Arguably the biggest name to move between the two clubs, Cole joined Chelsea in 2006 after coming through the ranks at Arsenal and winning two Premier League titles, with the second of those as part of the "Invincibles".
Cole enjoyed further success at Stamford Bridge, winning another league title, four FA Cups, a League Cup, the UEFA Champions League and UEFA Europa League, cementing his legacy as one of the best left-backs to ever play in the competition.
William Gallas (Chelsea to Arsenal, 2006)
As part of the deal that led to Cole moving to Chelsea, Gallas joined Arsenal.
After winning two PL titles at Stamford Bridge, the French defender spent four seasons with the Gunners, making 101 league appearances, before moving to a third London club, Tottenham Hotspur, in 2010.
Lassana Diarra (Chelsea to Arsenal, 2007)
Limited to only 13 PL appearances in two years at Chelsea, Diarra was sold to Arsenal in 2007.
The French midfielder was also unable to establish himself at Emirates Stadium, featuring only seven times in the league before joining Portsmouth five months later.
Yossi Benayoun (Chelsea to Arsenal, 2011)
A fringe player at Chelsea, Benayoun moved on loan to Arsenal for the 2011/12 season.
The Israeli enjoyed more success in north London, scoring four goals in 19 appearances, and his influence helped the Gunners finish third and qualify for the UEFA Champions League.
Petr Cech (Chelsea to Arsenal, 2015)
The Czech goalkeeper won the lot at Chelsea; four Premier League titles, four FA Cups, three League Cups, the UEFA Champions League and UEFA Europa League.
He moved to Arsenal in 2015 and won the Golden Glove award in his first season at the club, keeping 16 clean sheets, before picking up another FA Cup winners' medal in 2016/17.
Olivier Giroud (Arsenal to Chelsea, 2018)
Although Giroud struggled to hit the heights of the player he replaced at Arsenal, Robin van Persie, he did win the FA Cup three times for the Gunners.
The Frenchman made the move to Chelsea in 2018, and while he often struggled to hold down a first-team place, Giroud did pick up FA Cup, UEFA Champions League and UEFA Europa League winners' medals with the Blues, including scoring against Arsenal in the Europa League final.
David Luiz (Chelsea to Arsenal, 2019)
A PL winner with Chelsea in 2016/17, David Luiz followed in the footsteps of Cech and made the switch to Arsenal in 2019.
But while he lifted the FA Cup with the Gunners in his first season with the club, the Brazilian's stay in north London was short-lived, with the centre-back returning to his native Brazil in 2021, joining Flamengo.
Willian (Chelsea to Arsenal, 2020)
The Brazilian was an important member of Chelsea's title-winning sides in 2014/15 and 2016/17.
Despite starring on his Arsenal debut after joining on a free transfer, assisting two goals in a 3-0 win at Fulham, he only managed one goal and three assists over his subsequent 24 appearances before re-joining his boyhood club Corinthians in 2021.