He may have been just another courtier to Louis XIV but eventually he became famous many years after his death because of his wonderful if biased "Memoirs".
His father had been a favourite of King Louis XIII and, at his baptism at the Palace of Versailles, he had as his sponsors King Louis XIV and Queen Maria Theresa. Born in 1675, he appeared at court in 1692 and seemed destined for a brilliant career.
At the age of twenty, already a captain in the cavalry, he married the daughter of his superior officer, Marechal de Lorges, and became the father of three children. While on command at Ginesheim, he started to write his memoirs which would cover sixty years of his life. However, his military career did not last long. He had served no more than five years when the peace of Rijswijk was signed and he never saw active service again.
Expecting still greater things, he felt offended by an appointment he considered unjust and resigned his commission in the army. In his usual arrogance he maintained that: "Duke and peer as he is, with wife and children, he could not serve in the army like any upstart, or be thrown in contact with a different social class than his own, those holding office or commanding regiments."

Returning to Versailles, he remained a simple courtier for a long time. Accepted by all, including Louis XIV, he was in a unique position to make his observations; however, as he disliked Louis XIV his memoirs were somewhat slanted against the king. Morever, the dislike was mutual as Louis XIV was displeased with him for both his leaving the army and his pedantic meddling in support of the petty privileges of the class to which he belonged. Louis XIV never bestowed
notice upon him and sometimes even appeared cold towards him.Nevertheless, he tried to be as honest as possible. He also recognised the danger of Louis XIV's allowing power to the middle classes which inevitably was to lead to the French Revolution. However, he was in favour of the Duke of Orl‚ans, the future Regent of France, as he had been befriended by him.
He spent much of his time trying to turn the nobility into a political faction. When the Duke of Orl‚ans became Regent of France, he expected to become influential and so direct the affairs of France. However, when this position was taken by Cardinal Dubois, he left the court and from then on lived in retirement. The rest of his life was spent between the castle of Verte-Vidame near Chartres and his house in the Rue de Grenelle in Paris.
It took him ten years to write the final version of his memoirs, amounting to 2,300 pages. After his death these memoirs were found by the Duc de Choiseul who, fearing publication, placed them in the archives of the Ministry of Foreign affairs, where for sixty years only privileged people were allowed to read them. Finally it was King Louis XVIII who allowed the return of the memoirs to the heirs of the Duke de Saint-Simon.
 

Source: Leo van de Pas