After the 2000-2001 season, Arsenal were not looking to be major movers in the transfer market. Apart from the usual clearouts and comings-and-goings (that was Lee Dixon's last season, and Kolo Toure's first, for example), Arsenal, who had finished second to Manchester United, weren't in the market for any serious upgrades. Like any club, they were always looking, but there were no braying Twitter masses to try to convince them to sign everyone, and things were humming along fairly well for the club.
June 30 is the date when all player contracts that expire in a given year actually expire. July 1, then, starts a feeding frenzy for out-of-contract players; they all want homes, and clubs pick over them like vultures over a dead cow, trying to find good fits.
It was thought at the time that Sol Campbell would re-sign with Tottenham. They had, after all, offered to make him their highest-paid player ever; he was well on his way to becoming a club legend, and all he had to do was sign a new contract to basically cement his status as an icon in N17.
So of course, he signed with Arsenal. For nothing.
In the course of the season, and particularly in May/June, he said there'd be no way he would sign with Arsenal; players don't usually care about rivalries nearly as much as fans do, but there are very few truly great players who move from, say, Rangers to Celtic or vice versa, and I can count on one hand the number of great players that have swapped ends of the Seven Sisters Road, and still have fingers left over. So it's fair to say this was a huge deal - an excellent player, in his prime, moving to his club's biggest rival on a free? Unbelievable.
The news was greeted about how you would expect - Sol's still persona non grata for a large swath of the blue and white fan base, and while he didn't approach "gonna build him a statue" level awesomeness at Arsenal, he had a really good run, he was instrumental in the Invincibles season, and he can at least say he won a title at White Hart Lane.
So on this day, while we wait for Higuain, Rooney, Messi, Ronaldo, or whoever else Arsenal might sign for a lot of money, take a second, dig through the YouTubes, and find some Sol Campbell Arsenal highlights to celebrate the best free transfer in Arsenal's history, which will brighten your day as much as it will darken the day of the not-so-noisy neighbor. July 3 was a good day.
(In reading up for this piece, I learned that Sol Campbell's full name is Sulzeer Jeremiah Campbell. I always liked Sol, but Sulzeer is a really cool name too.)