Yanlesom thank you, I transferred to more learned than me ...

This button is very particular bill is more similar to the buttons Irish used in the English army fighting in the U.S. and Canada in 1812.
This is a priori lyre surmounted by the crown of the province of Munster, not that of King George who usually surmounted the lyre.La motto: Prosperity to Ireland n has no military! Unlike a similar button that you will find on the net "Volunteers Regiment Royal Dublin"

http://www.civilwarpreservations.com/catdet.asp?TargetItem=MG307&CategoryType=Buttons2

I do not think that this button comes from the Russian campaign at this time
The regiment was highly structured in three battalions, and had a uniform regulatory and buttons
I am enclosing a photo of a single copy found by me.



I have also owned the other button marked "Irish Regiment" button again, and French was not of Irish origin. This button has never set foot in Russia, especially as the regiment at that time no longer had a lot of Irish in these rankings, only 65 !!!!!

Thank you to my friend Pascal Dumeaux precise explanations for these

confusion

This button Regiment Irish date of the revolutionary period
one with the eagle of Napoleon comes after the first

in Russia they belonged to the 3rd Foreign Regiment not Irish!!
where there 's were not only Irish, some nations
were even higher represented ..... not to be confused!!