A marquess is a European title of nobility. Traditionally, a marquess was a count (or in England, an earl) who was offered the greater responsibility of guarding a frontier district. These territories are known as a marquessates. The original significance of the title has since been lost. In the United Kingdom the hereditary title may only be awarded by the Monarchy.
A British marquess is addressed as “The Most Honourable the Marquess of ...”and informally referred to as Lord, and his wife as Lady. In British peerage the heir of a nobleman is offered a courtesy title at least one rank below that of their peer. Therefore, the heir of a dukedom would be known as the “Marquess of ...” (the address would drop “the most honourable” to differentiate between a hereditary title and that of a marquess in his own right). Moreover the eldest son of a marquess would inherite the rank of earl, or viscount.
Popularity of Marquess
The title was the last to be introduced into the British peerage, and took a long time to become popular in the early stages of its creation. The first marquess in England was the earl of Oxford, Robert de Vere, who was made marquess of Dublin in 1385 by Richard II. Less than a year after this appointment he was raised to duke of Ireland. The second marquess was John Beaufort, earl of Somerset, who held the title of marquess of Dorset for less than two years before he was disgraced and his marquessate was revoked in 1399. Some three years later Richard II offered to reinstate him. The earl refused the title, claiming it had foreign connotations. More than forty years passed before the next creation of a marquess. The title was revived by Henry IV in 1442.
The feminine form of the title is marchioness, or marquise. The only lady ever to be made a marchioness in her own right was Lady Anne Boleyn, who became the marchioness of Pembroke in 1532.
In modern times, there are 34 remaining marquessates in the United Kingdom.
Biographies
I've added a couple of selected biographies - I'll be adding more when I can.
