But in how good a shape does it leave the Gunners for the next few months?
John Cross has all the answers.
Are fans happy with this summer's transfers?
I think they are - with a bit of a caveat. Arsenal didn't get the holding midfielder they needed - and look a bit short defensively, too. The big deal was Alexis Sanchez for £33m and that's a game changer, a real world class signing.
Mathieu Debuchy is an upgrade on Bacary Sagna, Calum Chambers has been a revelation, David Ospina a good back-up and Danny Welbeck a good last minute deal. Excellent overall.
Best buy and why?
Calum Chambers. Arsenal have got one of English football's emerging talents for £16m and he can play centre back, holding midfielder in the future and right back. A really good deal.
Arsenal's summer spending - 2014/15
Was there one who got away?
For my money, Sami Khedira. There was genuine interest there but the overall package - transfer fee and wages - was expensive and there were some doubts over his fitness, after all he missed much of last season with a knee injury.
Arsenal needed a holding midfielder and it's a shame they didn't get one. But word is that Khedira also may have something lined up next summer when he's a free agent. Watch this space.
Is the squad better than it was at the start of the summer?
Unquestionably. Arsenal look much stronger. They have bought well, they also responded on deadline day by signing Danny Welbeck to address a striker crisis. Welbeck is an excellent signing - full of pace, power and potential.
Who's been left in the cold?
It's a big left field, but Joel Campbell. I don't think he'll get much of a look-in and Arsenal thought about letting him go which suggests they don't see him as much of a first teamer despite his impressive performances in the World Cup.
Where do they still need to strengthen?
Holding midfielder. Plus a centre half. At the moment, they only have a back-up of Chambers to cover if Laurent Koscielny (currently nursing an Achilles injury) and Per Mertesacker. Nacho Monreal may play the odd game there. But it's a gamble.
I'm amazed they didn't get a centre half. They tried a few but Wenger didn't want to block Chambers' progress to the team. Chambers is too good to be stopped. And Wenger must worry about the club not individuals.
Will there be any more additions in January?
If you look in recent times, Wenger hasn't done much in January unless it's because of a glaring problem. Last year, they had a striker shortage so he bought an injured midfielder in Kim Kallstrom. That's Wenger logic for you. I think where you might see an addition is at centre half if there is an injury to Koscielny or Mertesacker. Why does Wenger always leave himself so short?!