St. John Paul II was ordained an auxiliary bishop of Krakow, Poland on September 28, 1958, the feast of St. Wenceslaus.
Among his first actions was to create an episcopal coat of arms, including a motto.
He chose the words, "Totus tuus," as his official motto as a bishop.
Later on John Paul II explained why he chose those words.
Totus Tuus. This phrase is not only an expression of piety, or simply an expression of devotion. It is more. During the Second World War, while I was employed as a factory worker, I came to be attracted to Marian devotion. At first, it had seemed to me that I should distance myself a bit from the Marian devotion of my childhood, in order to focus more on Christ. Thanks to Saint Louis of Montfort, I came to understand that true devotion to the Mother of God is actually Christocentric, indeed, it is very profoundly rooted in the Mystery of the Blessed Trinity, and the mysteries of the Incarnation and Redemption.
John Paul II also explained the full phrase it comes from in a Letter to the Monfortian Religious Family.
As is well known, my episcopal coat of arms symbolically illustrates the Gospel text quoted above; the motto Totus tuus is inspired by the teaching of St Louis Marie Grignion de Montfort (cf. Gift and Mystery, pp. 42-43; Rosarium Virginis Mariae, n. 15). These two words express total belonging to Jesus through Mary: "Tuus totus ego sum, et omnia mea tua sunt", St Louis Marie wrote, and he translates his words: "I am all yours, and all that I have is yours, O most loving Jesus, through Mary, your most holy Mother" (Treatise on True Devotion, n. 233). This Saint's teaching has had a profound influence on the Marian devotion of many of the faithful and on my own life.
He also put a capital "M" on his coat of arms in honor of the Virgin Mary. These features of his coat of arms would remain with him when he was elected pope.
At the conclusion of his first day as a bishop, John Paul II went with his friends to spend time at the Shrine of Our Lady of Czestochowa.
Thus, his entire first day as a bishop was spent consecrated to the Virgin Mary.