Pope Honorius IV issues a papal bull condemning the Apostolic Brethren as heretics. Founded by Gerard Segarelli around 1260, the Apostolic Brethren are a Christian sect that believes in returning to an apostolic way of life. They have no property, no fixed residence, and make no plans for the future.
They walk through cities preaching, singing hymns, and begging for food. Gerard Segarelli had tried to join the Franciscans but was rejected. The Apostolic Brethren movement becomes relatively popular with the people and has spread across Europe, but it's not well received by the Catholic authorities.
The Apostolic Brethren not only refuses to submit to the ban, but they start preaching against the Catholic Church itself. Gerard Segarelli will be burned at the stake in 1300.