I recently came across this story and was inspired. I hope to share more stories about St Dominic as I come across them.

One night, after continuing his prayers until midnight, Dominic left the church and came to the dormitory. He completed what he had to do and, taking his place at one end of the dormitory, continued to pray. As he stood praying, he glanced at the other end of the dormitory and saw three beautiful women enter. He noticed that the one in the middle was a venerable lady far more beautiful and dignified than the other two. One of them was carrying a beautiful, shining vessel, and the other an aspersorium that she handed to the lady in the center.

She went from bed to bed sprinkling the brethren with holy water and blessing them. As she went along in this way, she passed by one of them without sprinkling him or blessing him. Blessed Dominic observed this and took note of the brother they neglected. The lady said to blessed Dominic: “I am the one you call upon in the evening. When you say, Turn, therefore, most gracious advocate thine eyes of mercy toward us, I prostrate myself before my Son and ask him to preserve the Order.” After that blessed Dominic asked about the brother she had passed by as she sprinkled and blessed all the others. “Because he was not properly disposed,” she said. After this she continued to sprinkle and bless all the others and then disappeared. When she was gone, blessed Dominic returned to pray in the place he stood before. Suddenly he was rapt in spirit before God and saw Our Lord and the Blessed Virgin sitting at his right. It seemed to blessed Dominic that Our Lady was wearing a cape of bright blue, the color of sapphire. As blessed Dominic looked around, he could see religious of all the orders but his own before the throne of God. He began to weep bitterly and stood far away, not daring to approach the Lord and His Mother. Then our Lady motioned for him to come near. He would not dare, until our Lord himself also called him. Then blessed Dominic cast himself before them weeping bitterly. Our Lord told him to rise, and when he did, Our Lord asked him, “Why are you weeping?” Dominic said, “I am weeping because I see all other orders here but there is no sign of my own.” The Lord said to him, “Do you want to see your Order?” Dominic answered, “Yes, Lord.” Then Our Lord, putting his hand upon the shoulders of the Blessed Virgin, said to blessed Dominic, “I have entrusted your Order to my Mother.” Then the Blessed Virgin opened the cape that covered her and spread it out before blessed Dominic. It seemed vast enough to cover the entire heaven and, under it, he saw a large multitude of his brethren. Then, prostrating himself, blessed Dominic gave thanks to God and to Blessed Mary. After that the vision disappeared and he returned to himself just as the bell rang for Matins. When Matins was over, he called the brethren to Chapter and gave them a long and beautiful talk, exhorting them to love and pay reverence to the Blessed Virgin Mary. Among other things he related this vision to them.

—From the Narration on the Miracles of Saint Dominic by Blessed Caecilia

Source: http://www.op.org/en/content/under-our-ladys-mantle-0

In relation to the story here is a beautiful picture that was taken by Fr Lawrence Lew OP of a stained glass window in St Dominic’s, Dubrovnik: https://www.flickr.com/photos/paullew/1406656873/in/faves-141622777@N08/