Antoine Darquier, first discovered it in 1772.  Since their discovery, "planetary nebulae" have been the subject of intense study.  Herschel thought the Ring Nebula was composed of a ring of stars, but spectroscopy showed it to be composed of glowing gas.  In fact, there was a time that gas was believed to be a new element, Nebulum, though this was later determined to be doubly ionized oxygen.  Studies have shown that this nebula is roughly 1800 LY distant and expanding at a velocity of nearly 19 miles/sec. 

There are several other interesting and historic items in this constellation.  Epsilon Lyrae is the famed "Double-Double", comprised of four stars of 5th to 6th magnitude.  Beta Lyrae is a variable star with a period of 21.9 days, and a range of 3.4 to 4.4 

Another interesting star, RR Lyrae, is the prototype of its own class of short period variable stars.  This star has a period of 13 hours and 36 minutes, and a range of 7.0 to 8.1, you could almost watch this fellow go thru one cycle in a single night.  Study of this particular type of variable stars led to Harlow Shapley's discovery in the 20's that we are not in the center of the galaxy.