Late 3rd-mid 4th century AD, the period of the decline of Rome and invasion of Barbarians. See https://www.forumancientcoins.com/numiswiki/view.asp?key=Military%20Belts image 7 top left for an identical example identified as Sommer type 1.A.A. Just under 1 1/2” length with sheet plate and kidney-shaped buckle with decoratively scalloped front and original cross pin.
