These lines first appeared in the writings of Venerable Bede (died in A.D. 735), but they present several problems to the historians. To begin with, it is not clear whether Bede referred to the Colosseum or to the Colossus. In other sources, the lines are quoted slightly differently:

Quamdiu stabit colossus, stabit et Roma; quando cadet, cadet et Roma; quando cadet Roma, cadet et mundus. Bede, Opera Paraenetica 2, Excerptiones Patrum, Collectanea 543B [or in Migne 94].

Furthermore, Gibbon points out that there is no indication that Bede ever left England and, therefore, he may be quoting a saying already popular in his time among pilgrims to Rome.

Yet others attribute this saying to Byron, an error that goes back to the beginning of the 20th century.