to go on many military expeditions across the land; to fight in various locations over a long period

An idiom describing people's eager anticipation for the arrival of a benevolent army to liberate them; it originates from a historical account where people in the west complained when the army campaigned in the east first, asking why they were left for later

The series of religious wars initiated by Christians between the late 11th and 13th centuries to recover the Holy Land from Muslim rule; literally "the Crusaders' eastern expedition".