Sir John Franklin was a British Royal Navy officer and explorer who is best known for his ill-fated expedition to chart and navigate the Northwest Passage in the Canadian Arctic. He was also known by his initials, RAE, which are the three letters used to solve the crossword puzzle. Franklin's expedition set sail in 1845 with two ships, HMS Erebus and HMS Terror, but neither ship nor any of the 129 crew members were ever seen again.