The Comte de Provence & the Comtesse de Balbi

Louis Stanislas, Comte de Provence was well-established at Versailles as the brother of Louis XVI. As such he was entitled to a household paid for by the crown - and so was his wife.

It has been suggested that Anne Nompar de Caumont, Comtesse de Balbi had set her eyes on the royal brother and made him her target from an early stage. It was certainly whispered that that was the very reason why she sought employment with his wife, the Comtesse de Provence.

Anne, Comtesse de Balbi

Whatever the reason behind Anne's appointment she was made a lady-in-waiting to the Savoyard princess in 1780. Anne herself was already married to the Comte de Balbi with whom she had four children. Nevertheless, it was soon clear that the two had become engaged in a liaison. The Comte was said to only have taken the Comtesse de Balbi as his mistress because he was angry with his wife over her devotion to Marguerite de Gourbillon. If this was true then the commencement of his own relationship did nothing to further his marital bliss.
Later the Comtesse would go on to become dame d'atours to the Comtesse de Provence which can only have alienated the couple further.

As Anne's place beside Louis was soon firmly established he decided to honour her by building a pavilion for her. The pavilion was erected on a parcel of land within the gardens of Versailles; it would promptly be referred to as the Parc Balbi. The Comte would store a part of his massive book collection here.
When Louis purchased the Château de Brunoy he had a sumptuous apartment installed there for Madame de Balbi; furthermore he gave her a residence in Paris where the two could meet.

Louis, Comte de Provence

The Comtesse de Provence had turned her back on her husband over the affair but the reaction of the Comte de Balbi was far more violent. He was deeply angered by his wife's affair and made the mistake of openly protesting. The Comte de Provence did not care for this sort of charade and had the poor husband declared insane; he would be sent to an asylum where he would remain until his death.

When the revolution broke out the Comte and Comtesse de Provence escaped France - with them came the Comtesse de Balbi. It is widely assumed that she helped the two in organising their escape.

However, the husband and wife was due to split ways since the Comtesse wanted to return to her home in Savoy. As her lady-in-waiting Anne was obliged to follow her there and had to accept being apart from her lover. The relatioship would not last long after this. The reason for the eventual final split between Anne and Louis was the birth of a pair of twins during Anne's time at Savoy. These children could not have been the offspring of the Comte de Provence since the time gap between their last meeting was far too great.
Once the Comte de Provence learnt that his mistress had apparently been having other lovers he gave up the relationship.