Well, i m playing Irland campaign (late era). Actually game is in the year 1330 and gunpowder discover event was not start at the momment. Everyone knows that gunpowder recipe was know in europe about the middle of XIII century.
"The earliest extant written references to gunpowder in Europe are from the works of Roger Bacon. In Bacon's Epistola, "De Secretis Operibus Artis et Naturae et de Nullitate Magiae," dated variously between 1248[36] and 1257[37], he states:[36]
We can, with saltpeter and other substances, compose artificially a fire that can be launched over long distances... By only using a very small quantity of this material much light can be created accompanied by a horrible fracas. It is possible with it to destroy a town or an army ... In order to produce this artificial lightning and thunder it is necessary to take saltpeter, sulfur, and Luru Vopo Vir Can Utriet.

The last part has been interpreted as an elaborate coded anagram for the quantities needed, but it may also be simply a garbled transcription of an illegible passage.[38] [39]
In the Opus Maior of 1267, Bacon describes firecrackers:[38]
a child’s toy of sound and fire and explosion made in various parts of the world with powder of saltpeter, sulfur and charcoal of hazelwood.
[40] The Liber Ignium, or Book of Fires, attributed to Marcus Graecus, is a collection of incendiary recipes, including some gunpowder recipes. Partington dates the gunpowder recipes to approximately 1300.[41] One recipe for "flying fire" (ingis volatilis) involves saltpeter, sulfur, and colophonium, which, when inserted into a reed or hollow wood, "flies away suddenly and burns up everything." Another recipe, for artificial "thunder", specifies a mixture of one pound native sulfur, two pounds linden or willow charcoal, and six pounds of saltpeter.[42] Another specifies a 1:3:9 ratio."
Thanks for the help Cofeejunkie, but no works. Any more help?
*My english is terrible, i know. Sorry about that.