st. Volodymyr - Murderer Who Became a Saint

To the right of the main altar of St. Peter's Basilica in the Vatican is the Chapel of St. Volodymyr. It features a depiction of the prince holding a cross in his right hand and the Church of St. Sophia in his left. Volodymyr is honored as "the Great" and "Equal to the Apostles" for his role in the Christianization of Kyivan Rus. However, critics of the Catholic Church see the proclamation of Volodymyr, a man with a controversial past, as a saint to be the height of cynicism and hypocrisy.
Indeed, how could someone who raped Princess Rognida of Polotsk in front of her parents, and treacherously stabbed his own brother Yaropolk, be proclaimed a saint?