It is Women's History Month afterall! *S*

A widow with much desired lands in her possession, she was imprisoned, escaped (with help), imprissoned again, and escaped (with help) again, only to have her protector's castle laid seige to. It was only when she managed to have a letter smuggled to the most powerful man in Europe (at the time) offering to marry him, that she was finally free of her tormentor when, unable to resist her plea, her future husband came to her rescue. They did marry and were quite happy. Who was this bride of misadventure?