Robert, the child of Robert Dudley and Douglas Sheffield, was born in August 1574. His father appears to have been fond of him and oversaw his education. He went to Christchurch, Oxford and from there was apprenticed to a naval architect.
Somewhat surprisingly Elizabeth I didn’t appear to hold a grudge against Douglas Sheffield for her liaison with Robert Dudley – she even gave her a dress when she was pregnant with Robert and accounts suggest that the queen had a soft spot for the illegitimate son of her favourite.
When the Earl of Leicester died Robert who was the last remaining child inherited Dudley’s property including Kenilworth Castle but not the title – on account of his illegitimacy. When Ambrose Dudley died, Robert inherited land from his uncle as well.
In 1591 Robert was contracted to Margaret Vavasour with the approval of Elizabeth I but the bride wasn’t so keen on the match so married someone else and got herself banished from court. Dudley consoled himself by marriage to Margaret Cavendish in 1592 . Margaret Cavendish was part of the Suffolk family who were the senior line to the dukes of Devonshire. Margaret received two ships as a wedding gift from her father –who was an explorer as was her brother Charles Cavendish or other sources say that Dudley inherited two ships on the death of Charles. On Margaret’s death in 1593 Dudley married for a second time to Alicia Leigh in 1596, by whom he had four/fiveFerdinand II daughters.
In 1597 Robert was part of the raid on Cadiz with his step brother Robert Devereux, the Earl of Essex. Unfortunately he followed Essex a step too closely when he joined the earl in his rebellion. He was briefly imprisoned.
After the death of Elizabeth, Robert made a bid for legitimacy by claiming that his parents had been married in secret. The case was eventually heard by the Star Chamber but as his mother, who wrote a deposition, couldn’t remember the name of the cleric who married her and identified ten very dead witnesses it wasn’t a case that particularly held water. Essentially Robert who inherited land under the term of his father’s will wanted to claim the title as well.
Inevitably there’s more to the tale. In 1605 he went to Italy which would have been fine apart from the fact that he was accompanied by Elizabeth Southwell, the daughter of Sir Robert Southwell -she was Robert’s cousin. She was disguised as a page and there was the small matter of Robert’s wife and family to take into consideration. When Robert refused to return home his property was confiscated. Undeterred Robert promptly turned Catholic and married Elizabeth Southwell in Lyons. From there he went into the service of Cosimo II., grand-duke of Tuscany. He became a map maker and an engineer. In 1620 the Holy Roman Emperor Ferdinand II recognised his title not only to Warwick which his uncle Ambrose had held but also to Northumberland – remember his grandfather, the Duke of Northumberland had been executed. The Duca di Nortombria died near Florence on the 6th of September 1649, leaving a large family.