Flatbow is a broad term which includes many examples of bows from all over the world and throughout history.  Defined by the wide, flat limbs - more or less rectangular in section - it is perhaps the most efficient straight-staved wooden bow design available.  Unlike on the crowned (rounded) bellies of the English longbows or backs of the prehistoric European bows, which concentrate strain to the central ridge of the crown, the respective stretch and compression of the back and belly of the flatbow are spread accross the entire width of the limb.  This means that the bow is less likely to break, so a shorter bow can be made to the same poundage as with other styles, or less suitable woods can be used to greater effect.

     Such bows have been attested in historical cultures, from ancient European, Indian and Finno-Urgic to Innuit and Native American, and are still used by the remote islanders of the uncontacted Sentinelese tribes in the Indian Ocean, amongst others, as a day-to-day tool.  In many historical examples of this design's usage, only poor quality woods were available to the bowyers, so the high efficiency was a necessity.  With colder climate cultures, such as the Fins or Innuits, yew proved to be not only rare, but too brittle for bow use at such low temperatures.  They would make flatbows from ash or birch instead.

The American Longbow

     The American longbow was developed in the early 20th century in the USA, as a result of empirical scientific analysis.  It closely  resembles designs used by some of the Native American tribes, although it is said to be the application of the findings, regarding efficient cross-sectional shape, to the English longbow, hence the name.  The long limbs are parallel edged for most of the length, tapering to a point towards the tips, while evenly tapering in thickness from the narrowed, deep, stiff handle section to the tips.

The Pyramid Bow

     Another variation on the standard flatbow design is the pyramid bow, so called as it achieves its tiller by tapering the edges more than by tapering the thickness, resulting in a pyramid-like shape in each limb when viewed from the back.  This was a design used by some Native American tribes, such as the Modoc from the California/Oregan region of the USA, and is a very efficient one, with very light limb tips for the draw weight, leading to faster arrows.