I would like to know the history of this marching song. It was used by the Wehrmacht, but may be pre-Nazi era.

It is included under Deutsche Volkslieder (German folksong) in ingeb.org, with German lyrics (Is this the original?).

Some websites cite Lyrics by Hans Jürgen Nierentz, Music by Heinrich Steiner.

The following translation is on several websites, with the heading English translation by "Arminius 1871.."
(The gray uniform does not seem to be the Wehrmacht M42 gray field uniform, so the lyrics of this version seems to be post 1935, and the composers listed above belonged to that era.

Fly, German Flag, Fly!

Soldier, my friend, prepare your steps, comrade!
Step under the guns!
So everybody has to be strong, comrade,
To honour our fatherland.
To the peace serves the grey uniform
and not to the war of pain.
We are bringing forth a new era in our young hearts.

The song at www.ingeb.org:
(I will post only the 1st. verse and chorus)

Flieg, deutsche Fahne, flieg!

Soldat, Kamerad, fass Tritt Kamerad,
Tritt unter die Gewehre!
So muss ein jeder mit, Kamerad,
Dem Vaterland zur Ehre!
Dem Frieden dient das graue Kleid Eud nicht dem Krieg des Schmerzen.
Wir tragen eine neue Zeit
In unsern jungen Herzen.

Cho,-
Die Fahne hoch! Marschiert!
Voran der Führer führt.
Mit unsern Fahnen is der Sieg,
Flieg, deutsche Fahne, flieg!

Any information about the history would be welcome.