Faith will claim anyone deemed heretic before the Protestant reformation, were in fact Protestants, so therefore they qualify as examples.
Then I guess the pagan Saxons that worshiped Saxon gods were actuall Protestants, and slain by Charlemagne for being Protestants.
"The Massacre of Verden, Bloodbath of Verden, or Bloody Verdict of Verden (German Blutgericht von Verden) was a massacre of 4,500 captive Saxons in October 782. During the Saxon Wars, the Saxons rebelled against Charlemagne's invasion and subsequent attempts to christianize them from their native Germanic paganism. The massacre is recorded as having occurred in what is now Verden in Lower Saxony, Germany."
Massacre of Verden - Wikipedia
It would appear that Hindus are also Protestants.
"Religious persecution took place by the Portuguese in Goa, India from 16th to the 17th century. The natives of Goa, most of them Hindus were subjected to severe torture and oppression by the zealous Portuguese rulers and missionaries and forcibly converted to Christianity"
Forced conversion - Wikipedia