The "first see", or primatial see, of a regional or national church is sometimes referred to as the Mother Church of that nation. For example, the local Church of Armagh is the primatial see of Ireland, because it was the first established local Church in that country. Similarly, Rome is the primatial see of Italy, and Baltimore of the United States, and so on.
This term is most often used among Roman Catholics as Holy Mother Church. The Church is considered to be a mother to her members because she is the Bride of Christ, and all other churches have had their origin or derived from her. Another term used in the Catechism is the title "Mater et Magistra" (Mother and Teacher). Pope John XXIII made this the title of his encyclical celebrating the seventieth year after Leo XIII's groundbreaking social encyclical, explaining that in this Mother and Teacher all nations "should find ... their own completeness in a higher order of living." Pope Francis said:
The Church is our mother. She is our "Holy Mother Church" that is generated through our baptism, makes us grow up in her community and has that motherly attitude, of meekness and goodness: Our Mother Mary and our Mother Church know how to caress their children and show tenderness. To think of the Church without that motherly feeling is to think of a rigid association, an association without human warmth, an orphan.
In Anglicanism, the Church of England gave rise to all the other Churches in the Anglican Communion, and as such she is considered the Mother Church. The Archbishop of Canterbury thus serves as the focus of the Anglican Communion.