protomartyr
noun
pro·to·mar·tyr ˈprō-tō-ˌmär-tər 
: the first martyr in a cause or region
Word History
Etymology
Middle English prothomartir, from Middle French, from Late Latin protomartyr, from Late Greek prōtomartyr-, prōtomartys, from Greek prōt- + martyr-, martys martyr
First Known Use
15th century, in the meaning defined above