In the Song of Roland I ran into a battle cry which escaped translation. The italics are not mine.

He saw the miscreant stretched on earth:

"Caitiff, thy threats are of little worth.

On, Franks! the felons before us fall;

Montjoie!" 'Tis the Emperor's battle-call.

And again

"Well fought," said Turpin, "our barons true!"

And he raised the war-cry, "Montjoie!" anew.

and again it appears:

The Emperor loves us for such brave blows!"

Around them the cry of "Montjoie!" arose.

So of course this is a battle cry, but I looked it up anyway. The term originates in the Song of Roland and is considered the battle-cry of Charlemagne, but there's no agreement on its etymology. Below are those listed by various encyclopedias.

  1. That the term is connected to marking stones (cairns) along roadsides.
  2. That the term is connected to Mons Gaudii a mountain from which Christian pilgrims to Jerusalem "would get their first glance of the city"

Wikipedia claims that the 'Montjoie' (cairns) of the first explanation may have meant "hold the line," but not everyone agrees.

My next step was to 'see' Jerusalem from Mons Gaudii, or Mount Rama. This proved difficult. Rama doesn't appear to be a well known mountain, so Google keeps bringing up images of a Hindu god. I manage to find an Italian blogger who posts an image of a Mons Gaudii, but here the term is used generally for any view of Jerusalem.

Mons Gaudii