He married Elizabeth of York, daughter of King Edward IV, she was a Yorkist and Henry was Lancastrian, so marrying her would unite the two houses and end the blood thirsty feuds. It would also make sure that she couldn’t challenge him to the throne, as she had a stronger claim. He also made sure he married her after his coronation, so people could not say that he simply gained the throne from his wife. This marriage resulted in the birth of Prince Arthur, cementing the dynasty.