History / Ancient Polish History thread [180]

Years ago I received a prayer card w/ a small bag attached that has soil in it. On the card it reads: Ziemia Meczenska Pratulina. I believe it is the soil where a religiuos battle was fought and many Polish people died. However, that is all that I can rememer. The front of the card shows people holding up a cross. It looks to be from centuries ago. Any information would be most appreciated. Thanks!