In late 1646, Queen Christina of Sweden initiated a correspondence with Descartes through a French diplomat and friend of Descartes’ named Chanut. Christina pressed Descartes on moral issues and a discussion of the absolute good. This correspondence eventually led to an invitation for Descartes to join the Queen’s court in Stockholm in February 1649. Although he had his reservations about going, Descartes finally accepted Christina’s invitation in July of that year. He arrived in Sweden in September 1649 where he was asked to rise at 5:00am to meet the Queen to discuss philosophy, contrary to his usual habit, developed at La Fleche, of sleeping in late,. His decision to go to Sweden, however, was ill-fated, for Descartes caught pneumonia and died on February 11, 1650.
Occasionalism is a philosophical doctrine about causation which says that created substances cannot be efficient causes of events. Instead, all events are taken to be caused directly by God himself. The theory states that the illusion of efficient causation between mundane events arises out of a constant conjunction that God had instituted, such that every instance where the cause is present will constitute an "occasion" for the effect to occur as an expression of the aforementioned power. This "occasioning" relation, however, falls short of efficient causation. In this view, it is not the case that the first event causes God to cause the second event: rather, God first caused one and then caused the other, but chose to regulate such behaviour in accordance with general laws of nature. Some of its most prominent historical exponents have been Louis de la Forge , Arnold Geulincx , and Nicholas Malebranche . 
As a Catholic    in a Protestant nation, he was interred in a graveyard used mainly for orphans in Adolf Fredriks kyrka in Stockholm. His manuscripts came into the possession of Claude Clerselier , Chanut's brother-in-law, and "a devout Catholic who has begun the process of turning Descartes into a saint by cutting, adding and publishing his letters selectively."  In 1663, the Pope placed his works on the Index of Prohibited Books . In 1666 his remains were taken to France and buried in the Saint-Étienne-du-Mont . In 1671 Louis XIV prohibited all the lectures in Cartesianism . Although the National Convention in 1792 had planned to transfer his remains to the Panthéon , he was reburied in the Abbey of Saint-Germain-des-Prés in 1819, missing a finger and skull.  His skull is on display in the Musee de l'Homme in Paris.