Cheryl Gillan was sacked as secretary of state for Wales and replaced by her deputy David Jones, as the prime minister decided he wanted a Welsh-based MP to do the job. The Wales Office also acquired its first - and so far only - Liberal Democrat, with Lady Randerson joining as an unpaid junior minister.
Mr Laws writes of the wider reshuffle across the UK government: "Other changes were less high-profile. The unheard-of Conservative MP David Jones became the new Welsh secretary.
"So low-profile was he that at the first meeting of the new cabinet, David Cameron's deputy chief of staff, the super-posh Kate Fall, turned to Lib Dem director of communications Olly Grender and said, rather too loudly, 'Olly! Olly! Who IS that new person over there on the end of the cabinet table? I've never seen him before! I assume he must be one of your Liberal people?!'
"Given Kate Fall's role in coordinating the Conservative part of the reshuffle, a somewhat bemused Olly Grender, rather relishing the moment, whispered back, 'He is one of yours, Kate, a Conservative! He's the new secretary of state for Wales - David Jones. Your boss just promoted him.' Kate Fall looked distinctly embarrassed. 'Olly! How awful that I didn't know,' she said."
Almost four years after that reshuffle, where are they now? David Laws lost his seat at the 2015 general election, David Jones is campaigning for "Brexit", while Olly Grender and Kate Fall are now both members of the House of Lords.
David Laws's recently-published account of the coalition government includes an inside account of the September 2012 reshuffle that saw big changes at the Wales Office.