On 31 May 1578, Martin Frobisher left Harwich with a fleet of 15 ships. It was his third voyage to the Arctic, and it was much larger than his earlier attempts.

The voyage still carried the old aim of finding a North-West Passage. English backers hoped the route might open trade with Asia by sailing north-west through the seas around northern North America. By 1578, though, the project had changed. The expedition was also tied to the belief that ore brought back from Frobisher’s earlier voyages contained precious metal.

That belief gave the voyage its scale. Frobisher was no longer leading a small search into unknown waters. He was taking ships, men and equipment north in the hope that the Arctic could bring wealth. The expedition also carried plans for a small English settlement. That made the voyage an early attempt to turn discovery into possession.

The plan was ambitious, but the evidence behind it was weak. The ore had been valued too hopefully, and the northern conditions were hard to control. Ice, weather, poor visibility and distance all worked against the expedition. One ship was lost, supplies were scattered, and the settlement plan was abandoned.

Frobisher still brought back a large cargo of ore to his backers, which may have appeared to be a success. The weakness at the centre of the project only became clear later. The material proved worthless. What had helped send a large English fleet into Arctic waters was not mineral wealth, but the hope of it.

The third voyage is useful because it shows Elizabethan exploration in its early, uncertain stage. It involved courage and seamanship, but also bad information, commercial pressure and claims made in places England barely understood.

The fleet that left Harwich on 31 May 1578 was part of a larger English push into Atlantic and Arctic exploration. Its failure is the point: hope, money and poor evidence had been enough to send 15 ships north.