The worldwide fellowship of the forty-four autonomous churches that make up the Anglican Communion has no formal structure other than 'bonds of mutual affection'. Until recent years, those bonds have held the Communion together effectively and the creative tension between autonomy and communion has been one of the outstanding achievements of Anglicanism. Now, largely because of issues around human sexuality, that informal network is under severe strain and for the first time in its history, the Anglican Communion is contemplating a form of constitution.