Katharina von Bora was a German nun who left monastic life to become the wife of the Protestant reformer Martin Luther, earning the affectionate title "Herr Käte" from her husband. After escaping a Cistercian convent in 1523 in a wagon filled with empty herring barrels, she found refuge in Wittenberg and eventually married Luther in 1525. Their marriage became the foundational model for the Protestant clerical family, challenging medieval monastic celibacy and demonstrating a partnership of mutual respect, love, and shared labor. She managed their bustling household at the Black Cloister, farmed land, brewed beer, and hosted theological debates at their dinner table. Her feast day or commemoration is observed in some Lutheran calendars on December 20.