Hornby had no patron once the Aberdeen ministry came to power in December 1852 and instead cared for his father's estate at Lordington and played no part in the Crimean War. Following a change of government, Hornby became commanding officer of the frigate HMS "Tribune" on the Pacific Station in August 1858. When he arrived at Vancouver Island with a naval brigade, he found that a unit of American troops was about to take over the San Juan Islands in a dispute known as the Pig War. Hornby used his powers of diplomacy to facilitate a peaceful handover of the islands to the United States.