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In page April 12:

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  • 627 – King Edwin of Northumbria is converted to Christianity by Paulinus, bishop of York.[3]
  • 1012 – Duke Oldřich of Bohemia deposes and blinds his brother Jaromír, who flees to Poland.[citation needed]
  • 1204 – The Crusaders of the Fourth Crusade breach the walls of Constantinople and enter the city, which they completely occupy the following day.[4]