Around this time of year there are feasts for two bishops who were also martyrs. Their feasts were/are May 7 - St. Stanislaus (1030 - 1079) and June 5 - St. Boniface (c. 672 - 754). St. Stanislaus was instrumental in Christianizing Poland and was Bishop of Kraków from 1072 until his death in 1079. Boniface (c. 672 - 754), called "Apostle of the Germans," was a missionary from England who advanced Christianity in the Frankish Empire and was the first archbishop of Mainz.
"The heavens shall confess Thy wonders, O Lord: and Thy truth in the Church of the Saints."
(from the verse for the Feast of St. Stanislaus)
Confitebúntur coeli mirabília tua, Dómine: étenim veritátem tuam in ecclésia sanctórum.