This is a fascinating and prolific writer, now coming back into fashion. She was born Eleanor Alice Burford on the 1st September 1906 in Canning Town, London, and her fascination for history was awakened by a childhood visit to Hampton Court Palace.

During the war, she spent a great deal of time in Cornwall, a particular inspiration for the Victoria Holt novels.Throughout her life historical buildings inspired her and evoked stories and characters using all of her aliases, including her three main ones cited in the question.

The Jean Plaidy books tend to be straight historicals, often concentrating on royal matters. The most popular ones include trilogies based on the life of Mary Queen of Scots, the French Revolution, and Ferdinand and Isabella of Spain. The Philippa Carr ones blend history and fiction following the life of one family, collectively known as the Daughters of England series. The earliest one, the "Miracle at St Brunos" is set in the late medieval period, with the latest taking us up to the 2nd world war. The Victoria Holt ones are "guilty pleasure" gothic reads, though the historical background is sound and well-researched. Especially popular ones include "Mistress of Mellyn" and "On the Night of the Seventh Moon". Her achievements were recognised by the Golden Treasure award of the Romance Writers of America in 1989.

A life-long lover of cruising, she died at sea near Greece at the age of 86 in 1993.

More Info: en.wikipedia.org