A native of the Swiss canton of Uri (he was probably born in Klingnau), Zwyer initially pursued a military career. From 1612 to 1617, he served in a mercenary regiment in the service of Spain and Milan; from 1619 to 1642 he was in service for the Habsburg emperors, first for Ferdinand II and then Ferdinand III.
Zwyer, born in Klingnau within the Swiss canton of Uri, began his military career. From 1612 to 1617, he served in a mercenary regiment for Spain and Milan; from 1619 to 1642, he was employed by the Habsburg emperors, first Ferdinand II and then Ferdinand III.