At an early age he was sent to a school in London and placed under the care of a kinsman, Sir John York, who in 1544 placed him on board a ship belonging to a small fleet of merchantmen sailing to Guinea. By 1565 he is referred to as Captain Martin Frobisher, and in 1571—1572 as being in the public service at sea off the coast of Ireland. He married in 1559.
It took him fifteen years to gain the necessary funding for his project. In 1576, mainly by help of the Earl of Warwick, he was put in command of an expedition of small ships. It consisted of two tiny barks, the Gabriel and Michael, of about 20 to 25 tons each, and a pinnace of 10 tons, with an aggregate crew of 35.
Some days later the mouth of Frobisher Bay was reached, and because ice and wind prevented further travel north, Frobisher determined to sail westward up this passage (which he conceived to be a strait) to see “whether he mighte carrie himself through the same into some open sea on the backe syde.”
Butcher's Island was reached on the 18th of August, where the expedition met some of the local natives. Five of Frobisher's men were decoyed and captured, and never seen again. After vainly trying to get back his men, Frobisher turned homewards, and reached London on the 9th of October.
Among the things which had been hastily brought away by the men was some "black earth," and just as it seemed as if nothing more was to come of this expedition, it was rumored abroad that the apparently valueless "black earth" was really a lump of gold ore. It is difficult to say how this rumour arose, and whether there was any truth in it, or whether Frobisher was a party to a deception, in order to obtain means to carry out the great idea of his life.
The story, at any rate, was successful. The next year a much bigger expedition than the former was fitted out. The queen lent the ship Aid from the royal navy and provided £1000 towards the expenses of the expedition. A Company of Cathay was established, with a charter from the crown, giving the company the sole right of sailing in every direction but the east. Frobisher was appointed high admiral of all lands and waters that might be discovered by him.
On the 26th of May 1577 the expedition, consisting, besides the Aid, of the ships Gabriel and Michael, with boats, pinnaces and an aggregate complement of 120 men, including miners, refiners, etc., left Blackwall, and sailing by the north of Scotland reached Hall's Island at the mouth of Frobisher Bay on the 17th of July. A few days later the country and the south side of the bay was solemnly taken possession of in the queen's name.
Several weeks were now spent in collecting ore, but very little was done in the way of discovery, Frobisher being specially directed by his commission to “defer the further discovery of the passage until another time.” There was much parleying and some skirmishing with the natives, and earnest but futile attempts made to recover the men captured the previous year.
The return was begun on 23 August, and the Aid reached Milford Haven on 23rd of September. The Gabriel and Michael later arrived separately at Bristol and Yarmouth.
Frobisher was received and thanked by the queen at Windsor. Great preparations were made and considerable expense incurred for the assaying of the great quantity of "ore" (about 200 tons) brought home. This took up much time, and led to considerable dispute among the various parties interested.
Meantime the faith of the queen and others remained strong in the productiveness of the newly discovered territory, which she herself named Meta Incognita, and it was resolved to send out a larger expedition than ever, with all necessaries for the establishment of a colony of 100 men. Frobisher was again received by the queen at Greenwich, and her Majesty threw a fine chain of gold around his neck.
On 31 May 1578 the expedition, consisting in all of fifteen vessels, left Harwich, and sailing by the English Channel on 20 June reached the south of Greenland, where Frobisher and some of his men managed to land. On the 2nd of July the foreland of Frobisher Bay was sighted. Stormy weather and dangerous ice prevented the rendezvous from being gained, and, besides causing the wreck of the barque Dennis of 100 tons, drove the fleet unwittingly up a new (Hudson) strait. After proceeding about 60 miles up this "mistaken strait," Frobisher with apparent reluctance turned back, and after many buffetings and separations the fleet at last came to anchor in Frobisher Bay.
Some attempt was made at founding a settlement, and a large quantity of ore was shipped. Too much dissension and discontent prevented a successful settlement. On the last day of August the fleet set out on its return to England, which was reached in the beginning of October. The ore apparently was not worth smelting. This ended Frobisher's attempts at the North-West Passage.
In 1580 Frobisher was employed as captain of one of the queen's ships in preventing the plans of Spain to assist the Irish insurgents, and in the same year obtained a grant of the reversionary title of clerk of the royal navy.
In 1585 he commanded the Primrose, as vice-admiral to Sir Francis Drake in his expedition to the West Indies, and when soon afterwards the country was threatened with invasion by the Spanish Armada, Frobisher's name was one of four mentioned by the lord high admiral in a letter to the queen of "men of the greatest experience that this realm hath," and for his signal services in the "Triumph," in the dispersion of the Armada, he was knighted. He continued to cruise about in the Channel until 1590, when he was sent in command of a small fleet to the coast of Spain.
In 1591 he visited his native Altofts, and there married his second wife, a daughter of Lord Wentworth, becoming at the same time a landed proprietor in Yorkshire and Notts. He found, however, little leisure for a country life, and the following year took charge of the fleet fitted out by Sir Walter Raleigh to the Spanish coast, returning with a rich prize.
In November 1594 he was engaged with a squadron in the siege and relief of Brest, when he received a wound at Fort Crozon from which he died at Plymouth on 22 November. His body was taken to London and buried at St Giles', Cripplegate.