Originally posted by Sir James
In British usage 'baron' is usually a generic term for a titled landowner (eg The Barons' War).
However, I recall references to a Baron Rothschild, who was I think British, but perhaps had a continental title.
A Baronet is generally referred to as "Sir John Smith, Bt" to show that he is not a mere non-hereditary knight. His wife, though, might be addressed as a Baroness (eg Thatcher), but perhaps this is only if the wife is, in fact, the intended beneficiary of the title.
The Thatchers are the only non-royal hereditary award I can recall from recent years.
Well, it's been a while since I last looked at a copy of Burke's peerage, but unless they have changed it, Baronets were hereditary knights, and as FrankJ originally posted, created by James I to fund the settlement of Ireland. I remember that there were supposed to be 3 groups and FrankJ has confirmed that. I didn't know they had been merged in 1707. I do remember that their heraldic symbol was a an open, white-gloved palm. Their wives can take the title of Lady, but not in their own name
This is similar to other English titles. I learned some of this from Dorothy Sayers, so I will use the fictional Wimsey family as an example. THe Duke of Denver is (or more appropriately since they had either already or will soon kick out most hereditary peers from the House of Lords) was a peer and member of the House of Lords. He has a secondary title, the Viscount Saint-Charles, which can be and is customarily used as a courtesy title by his eldest son and heir. Although his first son's courtesy title is that of a Viscount, which is technically 3 ranks lower than that of a Duke, according to Burke's peerage, his order of precedence places him one rank below his father (equivalent to a Marquess/Marchioness). Other sons and daughters would have precedence equivalent to 2 ranks below (an Earl/Countess). These other sons and daughters have the right to preface the title Lord/Lady before their FIRST NAME. Therefore, a 2nd son, Peter, would be called Lord Peter, but not Lord Wimsey. Lord Peter's wife, Harriet, born a commoner, would be addresses as Lady Peter, NOT Lady Harriet.
Anyway, for titled Nobility (and baronets are considered knights, not nobles), the rank from lowest to highest, according to Burkes's peerage, is:
Baron/Baroness
Viscount/Viscountess
Earl/Countess
Marquess/Marchioness
Duke/Duchess
The Lords of the Church have their place in this precedence as well, with Bishops falling between Barons and Viscounts and Archbishops falling between Marquess and Duke.
There are specific modes of address (Dukes and Archbishops are addressed as "your grace" as opposed to "my lord" or "your lordship"), as well as varying modes of written address (Right Honorable, Most Noble, etc.).
Only Prince Charles, when he became the Prince of Wales is a true prince in the sense that he has a real title of rank of prince. His brothers' prince titles are courtesy only, and their "real" titles of Duke of York and I forget what Andrew's was, were conferred when they reach adulthood.
In terms of life-peers (non hereditary nobles and members of the House of Lords), there are a LOT of them - they may even outnumber the hereditary ones. Traditionally, a retiring Prime Minister is given a life peerage, so Margaret Thatcher receving a baroness title was in accordance with practice, although I always thought retiring PM's were made Viscounts. But other commoners who have a long history of service to England are also given life peerages, and they come from all walks of life, not just politics.
Of course, this is for the UK only and other countries have their own systems, which can get quite complicated.
