Before ISIS destroyed this monument I have never heard of it, I tried Googling and could find much of the history. Why was it built? By whom? What year? So to honour this lost piece of history I would like to learn about it.
In short, the Arch of Triumph was built by the Romans in the second century AD in order to celebrate a Roman victory over the Persians. Absorbed into the Roman Empire in the first century AD, Palmyra was an important Roman outpost. The triple arch was built in the established manner of the Roman triumphal arch; it bore ancient inscriptions and stood at the entrance to a grand colonnade.