The ranks of the English peerage in descending order are:

• Duke

• Marquess

• Earl

• Viscount

• Baron

For our purposes a peer is defined as a member of any of these five ranks of the nobility in Great Britain and Ireland.

While most newer English peerages descend only through the male line, many of the older ones (particularly older baronies) can descend through females. Under English inheritance law all daughters are co-heirs, so many older English peerage titles have fallen into a waiting state between the various female co-heirs to see who the true title holder will be.

Oh, and there are Royal Dukedoms as well, such as the Duke of York which is normally bestowed upon the monarchs second son.

The general order of precedence among dukes is:

• Dukes in the Peerage of England, in order of creation
• Dukes in the Peerage of Scotland, in order of creation
• Dukes in the Peerage of Great Britain, in order of creation
• Dukes in the Peerage of Ireland, in order of creation
• Dukes in the Peerage of the United Kingdom, in order of creation

with the following exceptions:

• The Sovereign's Grace may accord any peer higher precedence than his date of creation would warrant - i.e. the ruling monarch can fiddle the list.
• The royal dukes are Dukes of the United Kingdom; but they rank higher in the order of precedence than the age of their titles would suggest, due to their close relationship to the monarch. The Prince of Wales holds precedence above all dukes, even royal dukes, although he is also the Duke of Cornwall and of Rothesay.
• Dukes of Ireland whose dukedoms were created after 1801 yield precedence to earlier created Dukes of the United Kingdom.

To be styled is to be allowed to use a courtesy title which belongs to your father (or possibly Grandfather) who is a peer and not currently using his lower ranking titles.

Courtesy peerages are only used by the peer's eldest son, and the eldest son's eldest son, and so on. Other descendants are not permitted to use the peer's subsidiary titles. Only the Heir Apparent (and the Heir Apparent to the Heir Apparent etc) can use the titles.

An Heir Presumptive (e.g. a brother, nephew, or cousin) does not use a courtesy title, since there is no absolute certainty that he will ever actually inherit the substantive title. However, Scottish practice allows the style 'Master/Mistress of X' to an heir presumptive as well as to an heir apparent.

The wives of courtesy peers are also entitled to courtesy titles, which are the female equivalents of their husbands' titles. Thus, the wife of Earl of Arundel is styled Countess of Arundel.

For the British peerage, written references to holders of courtesy peerages are supposed to be in the form "Marquess of Blandford", "Earl of Arundel", etc., i.e. without the preceding definite article ("The"); substantive (real) peers are named with the article, e.g. "The Marquess of Winchester", "The Earl of Derby".