Russian Tumblers
Interestingly enough, my go to first source for breed information, Levi's famous book "The Pigeon" does not mention Russian Tumblers. Instead I turned to the internet and have taken the following wonderful explanation of the breed from the National Russian Tumbler Club's site.
"The Russian Tumbler pigeon originated from the East Prussian Roller of Germany, whose early ancestors are believed to have been imported from Scandinavia in the 1700s as the Norwegian Tumbler. By the late 1930s they were known as Russian Tumblers in this country and East Prussian Tumblers were no longer imported to the US after World War II.
Over the years the conformation of the Russian Tumbler has become more compact, and powerful with longer feathers than its early ancestors. This cobby bird has a full, broad crest, oval head with pearl eyes (bull eyes allowed in whites only), large rosettes, a powerful neck and layered muffs of 3" to 4".
These even-tempered, small birds are economical to keep and make very good parents. One of the many beauties of this breed is the many colors; black, dun, red, yellow, brown, khaki, lavender and white selfs, combined with almond, kite, indigo, grizzle, dominate opal, rosewing, whitesides, baldhead, badge, saddle, magpie, white bib, moorhead, shield and mottle as well as bars, checks and T-patterns make this bird an inviting project bird for the fancier interested in genetics. You can create new patterns and colors, which will become recognized at future shows."