Before being retrofit with steam engines and reinforcements and being sent off under Franklin’s command to find the North West Passage, HMS Erebus and Terror had been sailed to Antarctica on a mission to map the earths magnetic field.

Franklin’s mission would end in disaster with his ice bound ships being abandoned and his surviving men devolving into cannibalism.

It would be 170 years before his ships would be located but the mystery of what happened, what doomed them, remains to this day.