The word tuba is a Latin word which was used to refer to a long Trumpet, with a length of over one metre.
A similar term, tubus, was used to refer to a special kind of trumpet used at sacrifices.
cornu
Cornu
The modern tuba is bent and the Roman tuba is a straight brass tube.
tuba
Tubicen
tubicen.
an ancient roman event
There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.There was no ancient Roman flag.
If you mean marching tuba, then it's called a sousaphone.
tubicen
tubicen
The Roman numeral M represents 1000. In ancient Roman use it did not always mean 1000, but it does today.