This fly was invented in May 1854, the place: Sprouston, Roxburghshire. Canon Greenwell, the fly-tier James Wright and schoolmaster Brown co-operated to produce the first Greenwell's. No matter whether it is tied as dry or wet-fly, the three men invented a great catcher.

Originally thought to imitate a particular olive Ephemerella, it represents practically the entire range of this species and catches fish throughout the season. In the acid mountain lakes of the North-West it is particularly useful when, on calm days with easterly winds, fish are rising but not taking very positively. The Greenwell's evolves then into a last resort-fly and often saves the day.

Hook sizes can vary from 12 to 14 or 16.

 

A more comprehensive history can be found at http://www.flyfishinghistory.com/greenwells_glory.htm