It has only been a relatively short time in fly fishing history that the fly reel has become important. This is due to several things: newer and better materials, fly fishing for larger species including salt water species and much improved drag systems. Gone are the days when a fly fishing reel was considered nothing more than a "place to store line". Things have "reely" changed...get it?
With changes in reel design and new technologies, there are more fly reels available than ever before. As more fly fishermen chase more and different species, the need for bigger and better fly reels also contributes to this growth in the fly reel industry. Many of the newer reels have larger arbors and drag systems are improving all the time.
Based upon what I have read, it was probably the Chinese that invented the fishing reel in 300-400 AD. Beyond reading several different articles on the subject, I could find no other specific evidence for this. There is very little else mentioned about fishing reels until sometime in the 17th century when there is another written reference to fishing reels when some obscure fisherman revealed that a "winder" was useful in landing larger fish. It should probably also be mentioned that the fishing line of the day was braided horse hair. These lines were fairly short and heavy and did not readily float. As a result, there was very little need for a reel. See more...