In 1577 Oxford invested £25 in the second of Martin Frobisher's expeditions in search of the Northwest Passage. In July 1577, he asked the Crown for the grant of Castle Rising, which had been forfeited to the Crown due to his cousin Norfolk's attainder in 1572. As soon as it was granted to him, he sold it, along with two other manors, and sank some £3,000 into Frobisher's third expedition. The 'gold' ore brought back turned out to be worthless, and Oxford lost the entire investment.