Ave Roma Immortails, Volume 1 by F. Marion Crawford

When the present Queen of Italy first came to Rome as Princess Margaret, and drove through the city to obtain a general impression of it, she reached the Piazza Colonna and asked what the column might be which is the most conspicuous landmark in that part of Rome and gives a name to the square, and to the whole Region. The answer of the elderly officer who accompanied the Princess and her ladies is historical. 'That column,' he answered, 'is the Column of Piazza Colonna' -- 'the Column of Column Square,' as we might say -- and that was all he could tell concerning it, for his business was not archaeology, but soldiering. The column was erected by the Emperor Marcus Aurelius, whose equestrian statue stands on the Capitol, to commemorate his victory over the Marcomanni.

It is remarkable that so many of the monuments still preserved comparatively intact should have been set up by the adoptive line of the so-called Antonines, from Trajan to Marcus Aurelius, and that the two monster columns, the one in Piazza Colonna and the one in Trajan's Forum, should be the work of the last and the first of those emperors, respectively. Among other memorials of them are the Colosseum, the Arch of Titus and the statue mentioned above.