This is the 1273rd most frequent Catalan word.
peu
"Peu" in Catalan means "foot" in English.
Here, 'peu' is used in its anatomical sense to denote the human foot.
Vaig colpejar una pedra amb el peu.
I hit a stone with my foot.
Here, 'peu' is metaphorical, referring to the base or foundation of the mountain.
El peu de la muntanya és un bon lloc per començar l'escalada.
The foot of the mountain is a good place to start the climb.
In this case, 'peu' illustrates the manner of movement, indicating that the soldiers were walking.