Richard Phené Spiers

“ The time involved in the construction of such a memorial, and more especially that which would be required for its enrichment with sculpture, rendered it impossible that they should be set up on the occasion of the triumphal entry itself, and it is known that the arch of Titus was not erected till some time after his death by his successor Domitian. There is always some difficulty in deciding between triumphal and memorial arches, as they were virtually similar in design, equally enriched with sculpture, generally surmounted with a quadriga and statues, and as a rule were isolated structures. ”

“ The triumphal arch with three arches at Fano in Italy is said to have been commenced by Augustus, but completed by Constantine, who probably added the two side arches and decorated it with inferior sculpture. At Timgad (Thamugada) in North Africa is a triumphal arch with central and two side arches, probably of Hadrian's time, and one with triple arches at Sbeitla (Suffetula) , also in North Africa, and another example at Saintes in France, built on a bridge. ”