His father pressured him to study law, but he rebelled and travelled to England and Germany, returning to France in 1699 when, upon receiving a large inheritance from his father, he bought an estate and took the name de Montmort.

He was friendly with several other notable mathematicians, and especially Nicholas Bernoulli, who collaborated with him while visiting his estate.

He was elected a fellow of the Royal Society in 1715, while traveling again to England, and became a member of the French Academy of Sciences in 1716.

De Montmort is known for his book[1] on probability and games of chance, Essay d'analyse sur les jeux de hazard, which was also the first to introduce the combinatorial study of derangements.

He determined in 1713 the sum of n terms of a finite series of the form where Δ is the forward difference operator, a theorem which seems to have been independently rediscovered by Goldbach in 1718.