It is a present participle (of the verb "conquer") used as an adjective.
Edit: when I thought about this some more, I realized that the problem might be a mistaken assumption that the present participle indicated an action in progress. This is not always the case: the action may have been completed in the past. Consider this sentence:
While the winning team accepted the trophy, the losing team applauded politely. Clearly, the "winning" and the "losing" have already happened -- and in this case, the Roman had conquered Zenobia several months before she had to march in chains.
👁 Thumbs Up :thumbsup: Thanks, GWB.
👁 Smile :)
In several dictionaries, the "winning" in "the winning team" is listed as an adjective, and in
Longman Dictionary of Contemporary English, "conquering" is listed as an adjective:
—conquering adjective
conquering heroes
Longman Dictionary of Contemporary English
My assumption was that
conquering is an adjective and used to indicate that the Romans had conquered Zenobia's empire before the procession.
