A little bit of fly rod history...
Based upon my reading and a little research, the very first reference to a fly rod was in a book published around 200 AD. The book was written by a Roman by the name of Aelian and he talks about the Macedonian fishing method in which dyed red wool was tied to a hook and then to a tree branch. They were quite heavy by any standard and the practice continued for hundreds of years and was still the practice when Izaak Newton wrote The Compleat Angler that was first published in 1653.
In the 17th and 18th centuries, the heavy sticks began to evolve as craftsmen began hollowing out the wood to reduce the weight. Next, the craftsmen began to experiment with various types of wood and eventually joined these pieces together to create the first ferrules and thus the first real fly rod came into existence. This in turn led to the development of fly rod tapers. Evidently, "greenheart" wood was the favored material of the time.
In 1845, an American by the name of Samuel Phillipe, a violin maker built what is thought to be the first split cane bamboo fly rod and bamboo quickly became the material of choice. The result was many American anglers began to develop new tapers and ferrule systems. The first split bamboo rods were built with 3 or 4 strips and this then became the 6 strip rods that are common today.
In the later 1800's, rod builders started making much more progress with split cane bamboo with the development of beveling machines that allowed for more consistent tapers. This, in turn, led to the creation of rod building companies such as South Bend, Hardy Brothers and Montague. Bamboo continued to be the material of choice until sometime in the 1940's.
In 1946, Dr. Howald, a military researcher and evidently a fly fisherman was the first person to incorporate fiberglass into a fly rod. It seems he broke is bamboo rod and used a fiberglass tube to repair it. This led to the first commercial fiberglass rods built by the Shakespeare Company. They wrapped fiberglass cloth around a mandrel and reinforced it with fiberglass "fibers" than ran along the length of the mandrel.
Fiberglass rods continued to improve and became much less expensive. Fiberglass was the material of choice until in 1973 when the first graphite rods were introduced. There is some confusion as to whether Fenwick or Hardy built the first graphite rod.
More recently, boron has shown some promise as a fly rod material but graphite continues to dominate the modern fly rod industry. One name in particular stands out when it comes to modern fly rod design...Don Green. He was the designer and builder of the first rods built by Fenwick and later was the founder of Sage (originally called the Winslow Rod Company).