ait fishing with a running line has been practiced for thousands of years, and we know that the Chinese fished with a running line in antiquity, but for whatever reason, the discovery was not documented in Europe in the fifteenth century. In the earliest known European reference to a fly line, the author of the Treatyse of Fysshynge with an Angle refers to fly fishing with a line that was fixed to the top of the rod.

The fixed line represents the first stage in the evolution of the fly line, and the author of the Treatyse gave precise instructions on how such a line should be made and attached to the rod. The line was constructed of twisted horsehair, with a simple loop to loop connection used to fix it to the rod tip. The horsehair was taken from the tail of a white horse, and then dyed, using among other things, small ale, alum, vitriol, copperas, walnut leaves, tanner's ooze and soot. The hair on to which the flies themselves were mounted was left in the natural state. The Treatyse contains an extremely detailed description of how to make fishing lines. In the fifteenth century, you had to be resourceful, or you didn't fish:

First see that you have an instrument like this picture drawn hereafter. Then take your hair and cut off from the small end a large handful or more, for it is neither strong nor yet dependable. Then turn to the top of the tail, each in equal amount, and divide it into three strands. Then plait each part at the one end by itself, and at the other end plait all three together. And put this last end in the farther side of your instrument, the end that has but one cleft. And fix the other end tight with the wedge the width of four fingers from the end of your hair. Then twist each strand the same way and pull it hard; and fasten them in the three clefts equally tight. Then take out that other end and twist it sufficiently in whichever direction it is inclined. Then stretch it a little and plait it so it will not come undone. And that is good. And to know how to make your instrument, behold, here it is in a picture. And it is to be made of wood, except the bolt underneath, which must be of iron.

From Walton onwards, very few authors ever seemed to agree about the ranking of different colours of horse-hair, and to make matters worse, there was considerable dispute about what sort of horse the hair should be taken from. The consensus favoured stallions, given that mares' tails became soaked with urine and were liable to be rotten as a consequence. One nuance of selecting hair was that the best hair came from horses whose tails were cut reasonably frequently, as this lessened the chances of selections containing damaged hairs. Given that it started in Walton's day, it is amusing to think that the argument over colour still continues, despite the fact that the materials have changed out of recognition in the intervening three hundred years.

Skilled fishermen fished for trout with lines that tapered to three or four hairs, and experts fished with lines as light as one hair; true light tackle fishing. Some of these stories ought to be taken with a pinch of salt; the breaking strain of a single horse hair is about four pounds, assuming that the hair is in good condition; if not, it can be much less. But the most important thing about horsehair lines is that they sink - in fact, unless the hairs are very loosely braided the only way to keep such a line on the surface is to keep it very short. Despite this, early anglers (in fact every angler up to the time that gut leaders began to be used late in the eighteenth century) fished flies which either floated, or at most fished a few inches deep in the surface film, partly because long rods weren't particularly common and partly because they knew that was what worked best. So the words 'wet fly' and 'dry fly' have no real meaning prior to the introduction of the gut cast; until the nineteenth century there was just one way of fishing a fly.

1. Horsehair is virtually rot proof and lines lasted so long that they were passed down from father to son, but it has some major drawbacks.

2. Getting good horsehair was tough even four hundred years ago - you need to find a stallion whose tail is regularly combed.

3. Knotted horsehair lines won't shoot. Plaited lines were made and some of them must have been very nice indeed, but it was a labour intensive task.

4. Horsehair has a tendency to 'pink' - loose ends break and stick out the sides of the line, catching on rod rings and anything else they can get a hold on.

5. Horsehair doesn't wind well around small diameter reel spindles, which were the rule until the last century.