The news that the Queen has made Prince Harry Duke of Sussex has led numerous American media outlets to try to explain the peerage to their audiences. Alas, their reporters often seem to struggle with the subject, so I thought I’d step up to the plate and provide a quick guide for anyone perplexed by what is admittedly a rather byzantine system. This post will focus on the British peerage–while Scotland, England, and Ireland each had their own separate peerages, they are now defunct.
There are five ranks within the peerage. From highest to lowest, they are: duke, marquess, earl, viscount, and baron. Despite these gradations, all peers are considered equal to one another, from the highest duke to the lowliest baron. However, baronets, knights/dames, and Lords of the Manor are not considered peers at all.
Historically, the right to attend Parliament has been the defining privilege of the British peerage. Initially, this was restricted to feudal barons, but by the thirteenth century, kings had begun summoning men to Parliament regardless of their landholdings. This eventually led to the development of purely titular dignities divorced from land tenure.
By the fifteenth century, the peerage had assumed its familiar five-rank structure. It had also become a hereditary institution, which meant monarchs had less control over the composition of the House of Lords. Most peerages went to the peer’s eldest son since primogeniture was the norm, but unlike Continental systems of nobility, the children of British hereditary peers are not peers themselves. This can get very confusing since many of these children bear courtesy titles. For example, the Duke of Norfolk’s eldest son is customarily styled ‘Earl of Arundel,’ but he’s still not a peer.
Once a peerage was created, its holders would enjoy a perpetual seat in Parliament, no matter how much they annoyed the king. Peerages could only be revoked by an Act of Parliament, and that rarely occurred. The fact that the each peerage created a perpetual seat in the legislature initially encouraged monarchs to be sparing with their ennoblements, but this changed under the Stuarts.
Faced with perpetual money problems, James I openly sold titles, including peerages. He ultimately created 62 peers (there were only 59 when he took the throne!). His successors were just as profligate: when the last Stuart monarch, Anne, died in 1714, there were 168 peers in the House of Lords (at one point, Anne had created 12 peers in a single day, which was more than Elizabeth I had created over the course of her forty-five-year reign!).
The succeeding dynasty, the Hanoverians, weren’t much better. George III was particularly liberal with peerages, though he was generally acting on the advice of ministers eager to win votes in the Lords. Political considerations ensured that the rate of creation remained high throughout the nineteenth and twentieth centuries.
By the 1950s, it was clear that something had to give. The House of Lords had become a dozy institution with many members who rarely bothered to show up. In a bid to reinvigorate the House, Harold Macmillan’s government introduced life peerages. This wasn’t a new concept, but until that point, life peerages had only been given to certain judges so they could take part in the House of Lords’ judicial work.
The Life Peerages Act 1958 allowed the Crown to confer baronies on individuals that would not be passed on to their descendants. It also specified that women were eligible for life peerages (female hereditary peers would have to wait until 1963 before they could sit in the Lords). Initially, hereditary peerages continued to be conferred alongside life peerages, but when Labour’s Harold Wilson came to power in 1964, he stopped the creation of hereditary peerages. Aside from a few exceptions under Margaret Thatcher, only members of the Royal Family have received hereditary peerages since 1964.
Male royals usually get dukedoms when they marry, but they also receive other titles as well. This ‘bundling’ isn’t unique to the Royal Family, but their subsidiary titles are usually more geographically diverse than those of other hereditary peers. Their earldom typically references a Scottish city, while their barony mentions a city from Northern Ireland. This is why Prince Harry became Earl of Dumbarton and Baron Kilkeel as well as Duke of Sussex. Members of the Royal Family often use these subsidiary titles when visiting the countries in question, at least in official contexts.
However, none of this applies to female royals. They don’t receive any titular honors when they marry. Instead, their husbands are offered hereditary peerages. Perhaps the most famous example of this was when Princess Margaret’s husband, Anthony Armstrong-Jones, became Earl of Snowdon upon their marriage. This is because a husband can confer status on his wife, but a wife cannot confer status on her husband. Giving a title to the man ensures that both spouses are covered, though this tradition seems to have fallen by the wayside in recent years.
Nowadays, hereditary peerages are entirely ceremonial in nature. The House of Lords Act 1999 removed most hereditary peers from Parliament, though 92 hereditary peers have remained in the House of Lords as a ‘transitional’ measure (you can read more about that here). In theory, any member of the Royal Family with a hereditary peerage could still sit in the House as one of the 92 excepted hereditary peers, but the Queen has prohibited them from doing so.
While the number of new hereditary peers has declined sharply, there is an ever-increasing number of new life peers—over 270 new creations in the past eight years alone. Unlike hereditary peers, life peers still enjoy automatic seats in the House of Lords. Most are nominated by political parties to bolster their ranks in the House, but a significant minority of life peers are non-partisan appointments (e.g., former civil servants or high-profile religious figures).
The fact that peers still play an important political role has ensured that their ranks have been received regular infusions of fresh blood. The nineteenth century saw prominent industrialists and businessmen appointed to the House, while the twentieth century saw the admission of trade unionists, scientists, social justice campaigners, and a diverse range of politicians. More needs to be done in order to make the peerage truly representative of modern Britain, but the newest candidates are usually far removed from the popular image of the wealthy toff.
 These were men who held lands directly from the king without any intermediate overlord. In return they were expected to provide the king with soldiers for his wars.
 Conversely, Scottish peerages remained tied to the land until the Union within England in the eighteenth century.
 The specific rules governing a title’s descent are set out in the Letters Patent which created it, and they can specify alternatives to primogeniture. For example, Earl Mountbatten of Burma had a special clause in his Letters Patent which allowed the title to pass to his eldest daughter.
 In 1983, Thatcher’s long-serving deputy, William Whitelaw, became Viscount Whitelaw, while the former Speaker of the Commons, George Thomas, became Viscount Tonypandy. The following year, former Prime Minister Harold Macmillan became Earl of Stockton. Neither Whitelaw nor Thomas had children, so their hereditary peerages became extinct on their deaths.
 Prince Edward bucked the trend by becoming Earl of Wessex (he allegedly chose this title because he heard it in Shakespeare in Love and liked it). However, it’s been announced that he will be created Duke of Edinburgh after his father dies.
 For example, the Earl of Stockton (Harold Macmillan) also received the title of Viscount Macmillan of Ovenden.
 One could argue that it would be better to give both spouses titles of their own in order to avoid the unfortunate implications of the present system.
 Even before the hereditary peers lost their seats, the Royal Family’s role in the House of Lords rarely extended beyond formally taking their seats.