The subsidiary titles are: Earl of Zetland (created 1838), Earl of Ronaldshay (1892) and Baron Dundas (1794). The title Earl of Ronaldshay is the courtesy title of the eldest son and heir of the Marquess.
Earl of Zetland was a steamer built by J. Fullerton of Paisley in 1877, for the Shetland Islands Steam Navigation Company, and was taken over by the North Company in 1890.
She was renamed Earl of Zetland II in 1939 because a new ship was expected, but the outbreak of war meant that she remained in service until the war was over.
Earl of Zetland was built by Hall Russell, Aberdeen in 1939, and was first in service at Lerwick on 14th August 1939, but due to the outbreak of war she was transferred to the Pentland firth service.
In 1600, after receiving confirmation of his lordship of Zetland, Earl Patrick built Scalloway Castle at Scalloway in the Shetland Islands to strengthen his control there against the position of Laurence Bruce, who had been appointed Sheriff of Shetland by his half brother, the deceased Earl Robert.
In 1607 Earl Patrick began the construction of the Earl's Palace in Kirkwall, the capital of the Orkney Islands.
Lord Robert was defeated and executed, and the earldom was forfeit to the crown, but was recreated in 1696 for George Hamilton, 1st Earl of Orkney, the husband of Elizabeth Villiers, recently discarded mistress of King William III.