The bend is such a bold and clear shape, clearly visible on the shield, that its popularity should not be a surprise. One of the Heralds primary roles is ensure that each coat of arms be distinct from all others Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 258 and one way to accomodate the demand for the use of the bend was to draw them with a variety of decorative edges, thus distinguishing, at least from close up, one set of arms from another. An edge which is decorated like the top of a castle wall is said to be embattled, or sometimes crenelle, from the original French. (In castle building terminology the parts of the wall that stick up are known as merlons, and the resulting gaps as crenels). A whole sub-section of heraldic terminology has sprung up to describe whether these crennellations appear on which edges, whether they line up or alternate, have additional steps or rounded tops. The interested reader is directed to the reference for the full set! A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Embattled For obvious reasons, use of this decoration is to be associated with castles and fortified towns, an early authority, Guillim suggest also some association with fire, but with out clear reason The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P41. In all, this is one of the more common, and most effective and appropriate of the decorative edges.