Strategy
Battleships are the most powerful warships afloat. They can sink most other vessels they meet (though they are vulnerable to submarine and air attack). Further, when attacking, Battleships cause collateral damage to other enemy naval units sharing the target's space. They can also bombard enemy city defenses.
Civilopedia Entry
The battleship was once the most powerful vessel on the seas. Heavily armored and difficult to destroy, its massive guns could accurately fire heavy projectiles at targets miles away. The battleship had two primary functions: clearing the seas of enemy ships and bombarding enemy coastal targets, usually in preparation for an invasion. The battleship's importance began to decline in World War II when the increasing use of fighters and bombers launched from aircraft carriers greatly extended the range of naval conflicts. Ship-to-ship combat became less frequent than long-range air attacks against enemy battle groups. The last of the U.S. Navy's battleships was decommissioned shortly after the Vietnam War, but the four battleships of the Iowa class were remodeled and re-commissioned in the 1980s.