Churchwarden pipes are identified by their pronounced, elongated stems, unlike most other pipe shapes which can be identified by the shape of their bowl forms and shanks. Although many believe that the extra stretch of stem provides a cooler, drier smoke, it's more likely that it simply aids in keeping smoke out of the eyes while enjoying a pipe. The German word for the configuration is actually Lesepfeife, or reading pipe.
The only requirement for a pipe to be considered a Churchwarden is its length — generally, anywhere from 9" to 18". Churchwarden stems may be bent or straight. The pipe's overall proportions should be taken into consideration as well; a rather large neo-classical piece might wear a stem of acceptable length, but its proportional relationship to the overall shape might not be so extreme as to render it a true Churchwarden.
Tobacco and pipe history at large is fraught with mystery and mystique, and the noble Churchwarden is no exception there. Some believe that the shape takes its name from night watchmen of churches, hearkening to a time when churches would always remain unlocked, with the distance between face and bowl allowing the "churchwarden" to smoke while keeping his line of vision clear. Others believe that the added length of stem allowed for the night watchmen to smoke with their pipes out of the church window, while some assert that the name is derived from the ability to rest the pipe on the church pew directly in front of the smoker. Regardless of however you imagine the church's night watchman smoking his faithful briar, it's clear that, in order to explore the shape's origins, one must step back, practically to tobacco's inception in the western world.
The Churchwarden was once as ubiquitous to the pipe smoking community as the noble tamper is today, with roots as far back as the late 18th or early 19th century (depending on who you ask). Though pipes have been produced from such materials as brass, pewter, and even lead, clay was the primary medium used in American pipe creation until the latter part of the nineteenth century. Longer clay pipes were among those seen in pioneer-era taverns, where they would occasionally be owned by the establishment for use by patrons. This convention is perhaps what grants the Churchwarden its colloquial association with moments of stationary respite, but, make no mistake, the elongated configuration stuck around well after the advent of the briar pipe. The shape retained popularity for quite some time, but fell out of fashion as the pipe smoking population became increasingly more mobile and in need of handier, more compact designs.
It was only after the early 2000's that interest in these longer-stemmed pipes saw a resurgence with the release of films like The Lord of the Rings trilogy. Today, many well-known makers and marques, such as Dunhill, Savinelli, Peterson, and Vauen, all offer these long-stemmed pipes, occasionally devoting entire lines to Churchwardens.
Whether you're in need of a reading pipe to keep the smoke out your eyes, enjoy the history and mythos surrounding the shape itself, or you simply want to look as regal as possible while enjoying a smoke, you should definitely consider adding a Churchwarden to your rotation.