64 - "I come from a long line of stubborn idiots!" -'It Happened One Night'
Some families pass useful things down the line from one generation to the next, and some objects of great sentimental or historical value. In the line of Wyndam-Pryces, one's inheritance, aside from a relatively comfortable financial status, is instead a profession-- the family business, as it were. For the better part of my family's existence, nearly every member has been, or has been associated with, the Watchers.
Sir Beckett Pryce was the earliest name I could uncover, when I researched this particular question. Sir Beckett traveled to the Middle East during the Crusades under the banner of Sir Richard the Lionhearted. According to family lore, Sir Beckett was attacked by a pair of vampires-- formerly Englishmen of his own regiment-- on the streets of Jerusalem one night, and was rescued by a "Saracen girl". Pursuing his rescuer, Sir Beckett met the Slayer's Watcher, and sought out the Council after returning to England.
Centuries later, Lady Emmeline Pryce, Duchess of... well, of some tiny county or other, was instrumental in ensuring the Council's continued existence beyond the reach and knowledge of the authorities. Lady Emmeline was an occasional companion of Queen Elizabeth I and introduced Her Majesty to the presence of the supernatural. From that time, the Watchers have enjoyed an understanding with the British crown and from it, the rest of the world's governments.
For her service to the monarchy, a marriage was arranged between Lady Emmeline's daughter Virginia Elisabeth to Sir Jasper Wyndam, a veteran of the wars against Spain and a firm believer in the supernatural himself, which made the family's continued association with the Watchers an almost given.
In the late Eighteenth Century, Thomas Wyndam-Pryce served the Council as one of its most successful "recruiters" of Potential Slayers. For whatever reasons, using the detection spells with which Watchers detect the young women who might possibly in line for the power of the Slayer was a simple affair for Thomas. He traveled the world almost constantly, from Italy to Hungary, and was the first Watcher of the modern era to visit China and Japan.
My father, Roger Wyndam-Pryce, has distinguished himself with decades of loyal service to the Council, both as a field agent and then as a senior member of the Council itself.
Then, there's me.
OOC Note: Obviously, this is a fanon response. Details, names, etc. are all the creation of the writer.