The Homburg is named after the Town Bad Homburg vor der Höhe near the Taunus Mountains near Frankfurt am Main in Germany, where is was worn since approximately the 1880s.   King Edward VII saw the hat there in the 1890s and liked it and made it popular as alternative to the Top Hat. 

One of the most elegant, meticulous and quite formal summer hat is the Summer Homburg made of straw or similarly light summery materials.  Less casual than the Panama Hat, it is part of the summer wardrobe.  It goes very well with a white dinner jacket.