The Iberians here are not Spaniards, but Georgians who settled in the monastery of Iveron on Mount Athos.
The Iberians’ icon of the Mother of God dates at least back to the 9th century. It was hidden by a pious widow of the city of Nicaea, during the iconoclastic persecution of the reign of Emperor Theophilus (829-842). A soldier found the holy icon and pierced it with his spear. Miraculously, the icon began to bleed. Since then, it is always represented with a small black mark on the cheek of the Virgin.
The widow obtained that the soldiers postpone the destruction of the holy image until the next day. During the night, she cast it in the sea. The icon was carried by the waves to Mount Athos. The monks there saw a pillar of fire on the sea reaching up to the sky. Going down to the shore, they found the icon, standing on the water. They placed it in the church at once, but somehow the next morning and the following days, it was found at the door of the monastery. The Mother of God revealed to a Georgian monk, who had brought it to the church that she wanted to guard the monastery gate. Since then, the icon found at the entrance of the monastery of the Iberians has been known as "Portaitissa," which means "Gate-Keeper."
A copy of this icon was sent to Moscow on October 13, 1648. This replica is also miraculous—many miracles occurred as soon as it arrived at the Novodevichy Convent in Moscow—and is one of the most venerated icons of Russia. The feast of its transfer is celebrated on October 13th in the Russian Church, and the icon is displayed for public veneration on feast days.