For all era : the classic reasons : ressources, expansion
Early:
1) wiping out a close civ to ASSURE a decent expansion in the future.
Middle :
1) helping another nation, reinforce links
2) harass nations ahead of me, via pillaging or only via distraction
Late: same as middle plus
1) disturbing civs going for cultural, space race wins, specially with harassing their costal cities with combined units tactic or nuke
.
Early:
1) wiping out a close civ to ASSURE a decent expansion in the future.
Middle :
1) helping another nation, reinforce links
2) harass nations ahead of me, via pillaging or only via distraction
Late: same as middle plus
1) disturbing civs going for cultural, space race wins, specially with harassing their costal cities with combined units tactic or nuke
