In 1722, the 15-year-old Frederick was inoculated against smallpox by Charles Maitland on the instructions of his mother, Caroline. His grandfather George I created him Duke of Edinburgh, Marquess of the Isle of Ely, Earl of Eltham in the county of Kent, Viscount of Launceston in the county of Cornwall, and Baron of Snaudon in the county of Carnarvon, on 26 July 1726. The latter two titles have been interpreted differently since: the "of"s are omitted and "Snaudon" rendered as "Snowdon".