Some time around her eighth birthday she was engaged to the son of Frederick II, the "Holy Roman Emperor." His name was Henry and he was two years older than Agnes. Furthermore, Henry has just been named Henry VII of Germany and crowned "king of the Romans." It would have been expected at the time for Agnes to move to her betrothed's region and begin to learn the culture and language. Yet, Frederick and Henry lived in entirely different regions and this custom proved implausible because of it. So, she was sent nearby to the area to live with Leopold VI of Babenberg. This seemed like a great accommodation and solution to the problem except for one detail: Leopold wanted young Henry to marry his daughter and not Agnes. It took some time but Leopold was able to connive and politic Frederick into cancelling the engagement and sending Agnes home. Henry ended up marrying Leopold's son and an alliance was cemented between the two families. After all, this was what it had been about the entire time. Agnes was a pawn in the game of royal politics and manipulations. Her father went to war with Leopold for this perceived slight. After this played out, she was engaged to Henry III of England to form a powerful alliance but Frederick refused to acknowledge it because of his own desire to marry Agnes. Finally, Agnes would have it no longer and stopped participating in the political game by declaring herself to be betrothed to Jesus because of the faith that had been steeping in her throughout all the political machinations.
She declared her intention of becoming a member of the Franciscan order of "Poor Clares" founded by Clare of Assisi. With the help of Church leaders she founded a hospital and convent on land given to her by her brother. She took vows of poverty, chastity, and obedience and in her daily work and charity she found the way of salvation. She personally cared for and healed lepers and provided food, beds, and clothing for the poor. When Frederick found out about her decision he was furious but he was then informed of her commitment. He is said to have responded, "If she had left me for a mortal man, I would have taken vengeance with the sword, but I cannot take offence because in preference to me she has chosen the King of Heaven." For the rest of her life she refused to be a part of a system that dehumanized women for political expediency and instead she became a force for charity and healing within both the Church and Bohemia. She died at the age of 81.