Why battleships carried torpedoes

What was the point of fitting torpedoes to battleships?

They were a carryover from expectations of close battle-line engagements, where torpedoes added another way to attack the enemy formation.

Torpedoes on battleships reflected an earlier tactical environment than the later long-range gunnery battle. When engagement distances were expected to be much shorter, a torpedo offered another weapon that a capital ship could discharge into the opposing line. The fitting persisted after the assumptions that produced it had begun to change. Doctrinal and procurement inertia can keep an awkward weapon in a warship design.