For Henry Luke Orombi, Anglican archbishop of Uganda, the topic for his chapel sermon on Friday, February 16, was an obvious choice. That is the day when Anglicans worldwide remember Janani Luwum, honored as a modern martyr. But this time, the commemoration of the Ugandan archbishop who confronted Idi Amin became the prelude to a fateful turning point for global Anglicanism. Once every three years, the top leaders of the world’s 78 million Anglicans, called primates, gather for consultation and study. In mid-February, 35 of the 38 primates assembled for the first time on African soil amid threat of Anglican...