Genealogist Charles Kidd, editor of Debrett's Peerage And Baronetage, said it was a good choice for the prince. "Cambridge was generally spoken of as a high possibility. It has a long royal tradition, and is immediately recognisable as an English title, it's one of those places everyone has heard of."
Professor David Carpenter, of King's College, London, said there may have been consideration of using the title of Duke of Clarence but it had some unfortunate associations. "Queen Victoria's grandson Albert Victor, who was second in line to the throne, was made Duke of Clarence when he reached full age, but he was a womanising philanderer who died in the 1890s."
Despite the long history of the city of Cambridge and the establishment of the famous university there in the early 13th century, it was not afforded the importance of a ducal title until the 17th century. From the 14th century until 1671 Cambridge was an earldom, but the title was elevated to a duchy during the re-established reign of Charles II in the 1660s, for a series of royal Stuart infants. All of these young boys were the sons of James Stuart, the Duke of York, who later became James II, the last Catholic monarch of England. James' children suffered greatly from youthful illnesses, and none of the four boys who were granted the title survived to their fifth birthday. Indeed, of the four sons granted the duchy, only two lived long enough to be formally invested with the title. These were officially the first and second creations of the duchy, and naturally due to the minority of the Stuart children there were no heirs to pass on the title to. (James' daughters were hardier than his sons. His first two daughters reigned as Queen Mary II (jointly with William III) and Queen Anne).
The duchy was left dormant for nearly 30 years after the death of James' fifth son in 1677. Then in the reign of Queen Anne in 1706 it was re-established in a third creation for George, the Electoral Prince of Hanover, who was the second cousin once removed of the Queen. He held the duchy for 21 years until the death of his father George I in 1727, at which point he acceded to the throne as George II. The duchy and all George's other British honours then 'merged into the crown' and ceased.
The duchy remained in limbo until the following century. In 1801, 74 years after George II became king, his son George III revived the title in a fourth creation for his seventh son, Prince Adolphus. Adolphus (b. 1774) spent most of his adult life soldiering, including during the Napoleonic Wars, during which he attained the rank of Field Marshal. From 1816 to 1837 he was also the Viceroy of the Kingdom of Hanover. Upon Adolphus' death in 1850 he became the first Duke of Cambridge to pass the title on to an heir, having held the title himself for nearly half a century. His only son Prince George (b. 1819) held the title for even longer than his father: by the time of his death in 1904 he had been the Duke of Cambridge for 54 years. George, like his father, was also a military man. He served in the army all his adult life, and was its commander-in-chief for a remarkable 39 years from 1856 until 1895. Wikipedia has this charming passage on his tenure at the head of the army:
Although he was deeply concerned about the welfare of soldiers, he earned a reputation for being resistant to doctrinal change and for making promotions based upon an officer's social standing, rather than his merit. Under his command, the British Army became a moribund and stagnant institution, lagging far behind its continental counterparts. In the late 19th century, whereas 50 per cent of all military literature was written in Germany and 25 per cent in France, just one per cent came from Britain. It is said that he rebuked one of his more intelligent subordinates with the words: "Brains? I don't believe in brains! You haven't any, I know, Sir!" He was equally forthright on his reluctance to adopt change: "There is a time for everything, and the time for change is when you can no longer help it."
George had three children but none were considered legitimate for the purposes of inheriting his titles. Upon his death in 1904 the duchy therefore once again lapsed. This time the title lay dormant for more than a century, until it was bestowed in its fifth creation on the newly-married Prince William, the current second in line to the throne.
William's Cambridge title is also joined by two other lesser titles representing the peerage of Scotland and Northern Ireland: he is also the Earl of Strathearn and Baron Carrickfergus. The Strathearn title has not been held for nearly six centuries, having lain dormant since the gruesome death of Walter Stewart in 1437, after he conspired in the murder of King James I of Scotland. For this crime Stewart was put to death in a most vicious fashion. According to Wikipedia:
Walter was tortured over a period of three days. On the first, he was put in a cart with a crane, hoisted up, dropped, and jerked violently to a stop to stretch his joints. He was then placed in a pillory and "crowned with a diadem of burning iron" bearing the inscription "King of all Traitors". On the second day, he was bound to a hurdle and dragged along the high street of Edinburgh. (Some claim he was also blinded and tortured with red-hot iron pincers on this day, but Buchanan speaks only of the hurdle.) On the third, he was disembowelled while alive, his entrails burnt before his face, and his heart was torn out and burnt. Finally, his corpse was beheaded and quartered, and the quarters displayed around the realm.
The barony of Carrickfergus in what is now Northern Ireland has been dormant since 1883. The 12th century Carrickfergus Castle is regarded as one of the best preserved castles in Ireland. Unlike his father William currently holds no Welsh title, although it is likely that he will be granted his father's title of Prince of Wales upon Charles' accession to the throne.
William's new wife holds no title of her own, and is therefore not known as 'Princess Catherine', despite being married to a prince. She will be known officially (and anachronistically) as Princess William, but it is doubtful that this would be much used in everyday parlance; her title of Duchess of Cambridge will be much more prevalent. She will also hold the courtesy titles of Countess of Strathearn and Baroness Carrickfergus.