I live in the Sant’Eustachio area of the ancient center of Rome. I thought on his feast day you might like to see a few photos:
Here is a view of the church named for this saint. It is a bit hard to get a view of the whole place, given its location.
Here is a closeup of the upper part. This is a marvelous view, with the graceful romanesque campanile juxtaposed to the sweeping curves of the baroque facade:
At the very top is the distinguishing emblem of the basilica and the saint:
You might know that all over Rome there are plaques from the time of Pope Benedict XIV (Lambertini) identifiying the different "rioni" of the City. Before WWII Mussolini wanted to created similar identifying monuments for the different regions and did so with fountains: the fountains of Rome. They were all done by the same architect and have unifying elements together with symbols relevant to each particular region of Rome. Here is the fountain for the area of Sant’Eustachio (Region 8). It is built into the side of the old seat of "La Sapienza", the great University of Rome. This is why you books. You also see the head of the stage, symbol of the region.
We just don’t know much for sure about St. Eustace. He might have been a 2nd c. martyr who had been in the Roman army during the time of Trajan. While hunting, he saw a vision of Jesus between the horns of a stag and converted, taking the baptismal name of Eustachius. After various adventures, he was killed during the time of Hadrian with his wife and children, by being roasted alive inside the abovementioned bronze ox.
St. Eustace is a patron of hunters and his story is somewhat conflated with St. Hubert. He is included in the list of the 14 so-called Auxilliary Saints, or "Holy Helpers".