By Ssolbergj - The vexillum of the Roman Empire was a red banner with the letters SPQR in Gold surrounded by a gold wreath hung on a military standard topped by a Roman eagle or an image of the goddess Victoria made of silver or bronze, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=4249122.
I gave my youngest student this picture of the vexillum. He loves history.