During the Prussian wars of the seventeenth century, Croatian mercenaries tied scarves around the collars of their shirts to hold them closed during battle. Owing perhaps to their usual dearth of logic, French aristocrats adopted the look and called their scarves cravats, after the French word for Croat. The look flourished in the eighteenth and nineteenth centuries to such an extent than Frenchman Honore de Balzac wrote a book about it.
In short order, cravats became bow ties. It’s not clear if neck ties evolved simultaneously or came later. Bow ties are found most often in two types: the bat-wing, which is parallel-sided like a cricket bat, and the thistle, also called a butterfly, which flares at the ends. More uncommon types include those with pointed ends and, very rarely, some with one pointed tip and one squared-off.
The more traditional bow ties are made in fixed lengths, usually between 14 and 20 inches, corresponding to the collar sizes of men’s shirts. Less pure types come in adjustable lengths. Fixed-length is preferred with formal shirts so that the adjustable buckles aren’t exposed at neck’s back.
Either way, bow ties are, by virtue of relative scarcity, indicative of individuality. As Warren St. John wrote in The New York Times:
“To its devotees the bow tie suggests iconoclasm of an Old World sort, a fusty adherence to a contrarian point of view. The bow tie hints at intellectualism, real or feigned, and sometimes suggests technical acumen, perhaps because it is so hard to tie. Bow ties are worn by magicians, country doctors, lawyers and professors and by people hoping to look like the above. But perhaps most of all, wearing a bow tie is a way of broadcasting an aggressive lack of concern for what other people think.”