This is not a complete picture, but it breezes by many useful, important, and just plain interesting personages, events, and trends of the Regency era. Lots of good, otherwise hard-to-find paintings and drawings of the time, with enough anecdotes to catch the reader's imagination and references if you're interested in verifying them or digging deeper.
A great book for getting an overview of Regency London. Originally published in 1971, the layout looks a little dated now and a few colour prints would have helped lift it, but the text is really instructive.