Thamks Bramblefind and Crusader!
Looks like it is a rare find with a Swiss Battailon of 660 men served under Napoleon in Spain! I like the well documented history of the Battailon. The button travelled back from Spain February 1811 to Wesel/Germany where the Bataillon become the 11th Regiment of light Infantry. The Bataillon was not formally disbanded until 16th Sep. 1811, at the depot of the 11th at Wesel. So this button was lost only a couple days marches of Wesel in a field close to the old road from Cologne to France. This road was built by the Romans, used by troops and civilians over 100s of years as one of the classic gates to Germany, the last time 1944/45 by american GIs.