Erlangen, the Franconian university town, where I (almost) live and where I went to university is known in German as ‘Die Hugenottenstadt’, in English the Huguenot town. This name reflects the religious conflicts within Europe in the 17^{th}century. The Huguenots were Calvinists living in a strongly and predominantly Catholic France. Much persecuted their suffering reached a low point in 1572 with the St Bartholomew’s Day massacre, which started in the night of 23-24 August. It is not know how many Huguenots were murdered, estimates vary between five and thirty thousand. Amongst the more prominent victims was Pierre de la Ramée the highly influential Humanist logician and educationalist. The ascent of Henry IV to the French Throne saw an easing of the situation for the Huguenots, when he issued the Edict of Nantes confirming Catholicism as the state religion but giving Protestants equal rights with the Catholics. However the seventeenth century saw much tension and conflict between the two communities. In 1643 Louis XIV gained the throne and began systematic persecution of the Huguenots. In 1685 he issued the Edict of Fontainebleau revoking the Edict of Nantes and declaring Protestantism illegal. This led to a mass exodus of Huguenots out of France into other European countries.

Franconia had suffered intensely like the rest of Middle Europe during the Thirty Years War (1618-1648) in which somewhere between one third and two thirds of the population of this area died, most of them through famine and disease. The Margrave of Brandenburg-Bayreuth, Christian Ernst invited Huguenot refugees to come to Erlangen to replace the depleted inhabitants. The first six Huguenots reached Erlangen on 17 May 1686 and about fifteen hundred more followed in waves. Due to the comparatively large numbers the Margrave decided to establish a new town south of the old town of Erlangen and so “Die Hugenottenstadt” came into being.

In 1698 one thousand Huguenots and three hundred and seventeen Germans lived in Erlangen. Many of the Huguenot refugees also fled to Protestant England establish settlements in many towns such as Canterbury, Norwich and London.

In the early eighteenth century Isaac Newton, now well established in London at the Royal Mint, would hold court in the London coffee houses surrounded by a group of enthusiastic mathematical scholars, the first Newtonian, eager to absorb the wisdom of Europe’s most famous mathematician and to read the unpublished mathematical manuscripts than he passed around for their enlightenment. One of those coffee house acolytes was the Huguenot refugee, Abraham de Moivre (1667–1754).

Abraham de Moivre the son of a surgeon was born in Vitry-le-François on 26 May 1667. Although a Huguenot, he was initially educated at the Christian Brothers’ Catholic school. At the age of eleven he moved to Protestant Academy at Sedan, where he studied Greek. As a result of the increasing religious tension the Protestant Academy was suppressed in 1682 and de Moivre moved to Saumur to study logic. By this time he was teaching himself mathematics using amongst others Jean Prestet’s *Elémens des**mathématiques*and Christiaan Huygens’ *De Rationciniis in Ludo Aleae*, a small book on games of chance. In 1684 he moved to Paris to study physics and received for the first time formal teaching in mathematics from Jacques Ozanam a respected and successful journeyman mathematician.

Although it is not known for sure why de Moivre left France it is a reasonable assumption that it was Edict of Fontainebleau that motivated this move. Accounts vary as to when he arrived in London with some saying he was already there in 1686, others that he first arrived a year later, whilst a different account has him imprisoned in France in 1688. Suffering the fate of many a refugee de Moivre was unable to find employment and was forced to learn his living as a private maths tutor and through holding lectures on mathematics in the London coffee houses, the so-called Penny Universities.

Shortly after his arrival in England, de Moivre first encountered Newton’s *Principia*, which impressed him greatly. Due to the pressure of having to earn a living he had very little time to study, so according to his own account he tore pages out of the book and studied them whilst walking between his tutoring appointments. In the 1690s he had already become friends with Edmund Halley and acquainted with Newton himself. In 1695 Halley communicated de Moivre’s first paper *Methods of Fluxions *to the Royal Society of which he was elected a member in 1697.

In 1710 de Moivre, now an established member of Newton’s inner circle, was appointed to the Royal Society Commission set up to determine whether Newton or Leibniz should be considered the inventor of the calculus. Not surprisingly this Commission found in favour of Newton, the Society’s President.

De Moivre produced papers in many areas of mathematics but he is best remembered for his contributions to probability theory. He published the first edition of *The Doctrine of Chances*: *A method of calculating the probabilities of events in play*in 1718 (175 pages).

An earlier Latin version of his thesis was published in the *Philosophical Transactions*of the Royal Society in 1711. Although there were earlier works on probability, most notably Cardano’s *Liber de ludo aleae*(published posthumously 1663), Huygens’*De Rationciniis in Ludo Aleae*and the correspondence on the subject between Pascal and Fermat, De Moivre’s book along with Jacob Bernoulli’s *Ars Conjectandi*(published posthumously in 1713) laid the foundations of modern mathematical probability theory. There were new expanded editions of *The Doctrine of Chance s*in 1738 (258 pages) and posthumously in 1756 (348 pages).

De Moivre is most well known for the so-called De Moivre’s formula, which he first

(cos θ + *i* sin θ)^{n} = cos *n* θ + *i* sin *n* θ

published in a paper in 1722 but which follows from a formula he published in 1707. In his *Miscellanea Analytica *from 1730 he published what is now falsely known as Stirling’s formula, although de Moivre credits James Stirling (1692–1770) with having improved his original version.

Although a well known mathematician, with a Europa wide reputation, producing much original mathematics de Moivre, the refugee (he became a naturalised British citizen in 1705), never succeeded in obtaining a university appointment and remained a private tutor all of his life, dying in poverty on 27 November 1754. It is claimed that he accurately predicted the date of his own death.

Did you mean to leave the statement of De Moivre’s formula incomplete?

Poking around, it seems that Stirling’s improvement was determining the constant sqrt(2\pi), which De Moivre had only computed numerically. I think nowadays when people say “Stirling’s formula”, they do include the constant. Deriving the exact constant is not that easy, although I guess for practical applications it doesn’t matter. Perhaps the most historically accurate term would be “De Moivre-Stirling formula.”

Not that historical accuracy has ever been the determining factor in mathematical terminology.

“Did you mean to leave the statement of De Moivre’s formula incomplete?”

No!

Emil du Bois-Reymond was descended from Huguenots on both sides of his family. His mother’s ancestors had lived in Berlin since the 17th century, and his father emigrated from the Swiss canton of Neuchâtel during the Napoleonic era. It was said that a quarter of Berlin was composed of Huguenots at the time Emil was born in 1818. As you argue, this was important for science. Du Bois-Reymond grew up speaking French at home, and his familiarity with enlightened French writers like Voltaire and Comte led him to his Positivist view of life. Indeed, his whole determinist outlook might be considered a form of secular Calvinism that he inherited from his father. Religion matters, even among the atheist.