The Black Army of Hungary.
There are many historic examples in which early muskets were decisive weapons:
- A few hundred conquistadors stomped through the Americas
- The Ottomans Janissaries totally owned persian bowmen and horse archers
- In Japan, muskets were introduced in 1543 by Portuguese merchantmen. After the Battle of Nagashino (1575), "arquebuses became a standard military asset in Japanese warfare. It is often cited as a turning point in Japanese warfare"
http://en.wikipedia.org/wiki/Battle_of_Nagashino
- The Battle of Cerignola, fought on April 28, 1503, between Spanish and French armies. It is noted as the first battle in history won by gunpowder small arms.
If you have an counter example in which longbowmen own even early and unreliable Muskets, please post it! In reality english longbowmen were really that: english. In the many european wars the bow proofed useless and battles were dominated by cavalry & pikemen (swiss mercenaries, german Landsknechts).