The Holy See Press Office released the official explanation of Pope Leo XIV’s coat of arms on Wednesday.

In the explanation, Fr. Antonio Pompili, Vice President of the Italian Heraldic-Genealogical Institute, highlights its Marian and Augustinian elements.

The Pope’s coat of arms includes the traditional papal symbols of the crossed keys of St. Peter and episcopal mitre.

The upper left-hand corner of the shield bears a silver fleur-de-lis set against a light blue background. On the bottom right, a red heart topped by a flame and pierced by an arrow sit atop a red book framed by an ivory background.

Pope Leo XIV’s motto—IN ILLO UNO UNUM (“In the One, we are one”)—sits at the bottom of the coat of arms.

The motto echoes St. Augustine’s sermon on Psalm 127, where he explains that “although we Christians are many, in the one Christ we are one.”

Fr. Pompili pointed out that the blue field evokes “the heights of the heavens and is distinguished by its Marian significance, with the lily appearing as the classic symbol of the Blessed Virgin Mary.”

The opposite field, he noted, contains the heart enflamed and pierced by an arrow, which is the emblem of the Order of St. Augustine, of which Pope Leo XIV served as Prior General for two terms.

“This figure symbolically evokes Saint Augustine’s words in the Confessions: ‘Sagittaveras tu cor meum charitate tua’ (“You pierced my heart with your love”),” explained Fr. Pompili.

From the 16th century on, the symbol has appeared in the Augustinian coat of arms.

It is typically accompanied by the open book, which symbolizes “the Word of God that transforms every human heart, as it did Augustine’s.”

“The book also recalls the enlightened works that the Doctor of Grace bestowed upon the Church and humanity,” noted Fr. Pompili. “White (in the papal arms rendered in ivory) recurs in many religious orders’ heraldry as a sign of holiness and purity.”

Source: vaticannews.va