While the exact origins of the arch are unclear, it is now generally agreed that it has nothing to do with the illustrious Roman general, Nero Claudius Drusus Germannicus (39 - 9 BCE).
Drusus was the son of Livia Drusilla (59/59 BCE - 29 CE) and the legal stepson of her second husband, the Emperor Augustus (r. 27 BCE - 14 CE). He was also the brother of the Emperor Tiberius (r. 14-37) and the father of the Emperor Claudius (r. 41-54).