Sinterklaas and Zwarte Piet arrive in The Hague

Saint Nicholas (Greek: Ἅγιος Νικόλαος, Hagios Nikólaos; Latin: Sanctus Nicolaus) (15 March 270 – 6 December 343), also called Nikolaos of Myra, was a historic 4th-century saint and Greek Bishop of Myra (Demre, part of modern-day Turkey) in Lycia. Because of the many miracles attributed to his intercession, he is also known as Nikolaos the Wonderworker (Νικόλαος ὁ Θαυματουργός, Nikolaos ho Thaumaturgos). He had a reputation for secret gift-giving, such as putting coins in the shoes of those who left them out for him, and thus became the model for Santa Claus, whose modern name comes from the Dutch Sinterklaas, itself from a series of elisions and corruptions of the transliteration of "Saint Nikolaos". His reputation evolved among the faithful, as was common for early Christian saints. In 1087, part of the relics (about half of the bones) were furtively translated to Bari, in southeastern Italy; for this reason, he is also known as Nikolaos of Bari. The remaining bones were taken to Venice in 1100. His feast day is 6 December [O.S. 19 December].

Sinterklaas [sɪntər'klaːs] (or more formally Sint Nicolaas or Sint Nikolaas; Saint Nicolas in French; Sankt Nikolaus in German) is a traditional winter holiday figure still celebrated today in the Low Countries, including the Netherlands, Belgium and Luxembourg, as well as some parts of Germany, French Flanders, Lorraine and Artois. He is also well known in territories of the former Dutch Empire, including Aruba, Suriname, Curaçao, Bonaire, and Indonesia. He is one of the sources of the holiday figure of Santa Claus in North America.

Although he is usually referred to as Sinterklaas, he is also known as De Goedheiligman (The Good Holy Man), Sint Nicolaas [sɪnt 'nikolaːs] [ pronunciation (help·info)] (Saint Nicholas) or simply as De Sint (The Saint).

He is celebrated annually on Saint Nicholas' eve (5 December) in the Netherlands and on the morning of 6 December in the other countries. Originally, the feast celebrates the name day of Saint Nicholas – patron saint of children, sailors, philatelists, and the city of Amsterdam, among others. Sint Nicholas being a bishop and this geographical spread make clear that the feast in this form has a Roman Catholic background, although the papacy has never officially recognized his existence.

Closely related figures are also known in German-speaking Europe and territories historically influenced by German culture, including: Switzerland (Samichlaus), Germany and Austria (Sankt Nikolaus); the region of South Tyrol in Italy; Nord-Pas de Calais, Alsace and Lorraine in France – as well as in Luxembourg (De Kleeschen), parts of Central Europe and the Balkans.

Christmas (Old English: Crīstesmæsse, meaning "Christ's Mass") is an annual commemoration of the birth of Jesus Christ and a widely observed holiday, celebrated generally on December 25 by millions of people around the world. A feast central to the Christian liturgical year, it closes the Advent season and initiates the twelve days of Christmastide, which ends after the twelfth night. Christmas is a civil holiday in many of the world's nations, is celebrated by an increasing number of non-Christians, and is an integral part of the Christmas and holiday season.

The precise year of Jesus' birth, which some historians place between 7 and 2 BC, is unknown. His birth is mentioned in two of the four canonical gospels. By the early-to-mid 4th century, the Western Christian Church had placed Christmas on December 25, a date later adopted in the East. The date of Christmas may have initially been chosen to correspond with the day exactly nine months after early Christians believed Jesus to have been conceived, and became generally associated with the southern solstice (i.e., the Roman winter solstice), with a sun connection being possible because Christians consider Jesus to be the "Sun of righteousness" prophesied in Malachi 4:2.