An apostolic vicariate is a territorial jurisdiction of the Catholic Church under a titular bishop centered in missionary regions and countries where dioceses or parishes have not yet been established. It is essentially provisional, though it may last for a century or more. The hope is that the region will generate sufficient numbers of Catholics for the Church to create a diocese. In turn, the status of apostolic vicariate is often a promotion for a former apostolic prefecture, while either may have started out as a mission sui iuris.