Fellow GAD-er and long-time virtual friend Curt Evans has a brilliant two-part article on "The British Golden Age of Detection's Deposed Crime Kings" at the American Culture; I strongly suggest you read it all.
Curt is right that the Crime Queens are not all there is to British Golden Age writing and tend to overshadow equally praiseworthy figures of the period. While the achievements of Christie, Sayers or Marsh (Allingham is an acquired taste, which I haven't yet acquired) are not to be denied or belittled, to equate them with Golden Age is both a fallacy and a rewriting of the past.
