The hermits of Mt. Carmel placed themselves under the protection of Our Lady. They saw here as their Patroness. The times were feudal. Having someone as patron meant having an advocate. It also meant belonging totally to that person. So in seeing Mary as Patroness they saw themselves as belonging totally to her and that she was their advocate.
This gave rise to the expression: Totus Marianus est Carmelus - Carmel belongs totally to Mary. Devotion to Mary as Mother and as a "sister in the Faith" would later become characteristic of Carmelites. Meanwhile, the hermits built in her honour a very beautiful little church. Soon after this, they were been referred to as "The Hermits of St. Mary of Mt. Carmel"