Erker was a Gottscheer, who were ethnic Germans descended from 14th century Tyrolean and Carinthian settlers to the then uninhabited Gottschee region, today's Kočevje in Slovenia.
On October 7, 1809, Gottscheer and some Slovene people in the border regions south of Gottschee attacked French troops who were in the villages collecting taxes.
In Neustadtl, the rebels were driven off thanks to the arrival of reinforcements under General Carlo Zucchi, the bravery and quick thinking of defending commander Captain Luigi Tarducci, and their own ineptitude.
On October 15, Johann Erker was inside the city of Gottschee when the French relief force of 1,000 led by General Zucchi approached from the southeast.
On the morning of October 18, 1809, a nine-man firing squad was organized facing the side of the parish church dedicated to St. Bartholomew, and one by one the rebel leaders were led out to die.