An Unusual Image of the English Martyrs

Continuing the series of paintings in the choir of Corpus Christi, Krakow, dating from 1624-32, here is what purports to be a most unusual depiction of the English Martyrs. According to the English guide book, the painting shows 'a group of Canons' saints murdered in England in 1572'. The Latin inscription below the picture also clearly links the group of martyrs to England: Milliadena Necat Sancti Gregis Anglia Christo/Non Alit Illa Lupus Induit Ipsa Lupum.

I don't know where 1572 came from - there seems to be no date on the painting or on the inscription. Perhaps the author of the guide book confused the English Martyrs with the group of priests and religious (including two Norbertine Canons) who suffered at Gorkum in the Netherlands in 1572. There were no English Martyrs in 1572.

As far as I know, no Canons Regular suffered for the Faith in England and Wales. Perhaps the seventeenth century canons of Krakow imagined the new breed of seminary priests in distant England to be canons regular and thus depicted them in canons' habits?