campaign

From French campagne, from Italian campagna ("field, military operation"), from Late Latin campānia ("open country, battlefield"), ultimately from Latin campus ("field").

The word traveled from a plain, open field to the battlefield operations conducted on such fields, and from there settled into English as a name for any organized, sustained effort.

It's a doublet of campania, campagna, and champagne — all tracing back to that same open field, Latin campus.