We do know that the Romans of the last few centuries BCE were building "triumphal" arches to welcome ... with a diamond-shaped keystone (the Gothic arch, model C). Flying buttresses act the same way ...

It’s worth noting that, contrary to widespread belief, there is no record of a Roman arch being built for its honoree’s triumphal procession. Though commissioned by victorious generals, the earliest ...

Finished in 315 C.E., the Arch of Constantine is one of Rome’s three surviving ancient triumphal arches ... himself to Christianity—the first Roman ruler to do so. The fierce storm also ...