A Papal Bull is an official decree or letter issued by the Pope, the leader of the Roman Catholic Church. It is named after the bulla, a seal that is affixed to the document to authenticate it. Papal Bulls can address various matters, including doctrine, church governance, and important announcements. Historically, Papal Bulls have played significant roles in shaping church policy and influencing political events. For example, the Inter caetera bull issued by Pope Alexander VI in 1493 granted Spain and Portugal rights to colonize the Americas, impacting global exploration and colonization.