On 30 November 1813 prince William , son of the former stadholder of the Dutch Republic William V, returned to the Netherlands after having lived in exile for eighteen years. While the nation was gradually being liberated from French troops he successfully negotiated that his territory would be augmented with the Belgian provinces. On 16 March 1815 he proclaimed himself as the king of the United Kingdom the Netherlands. This meant two important changes: for the first time the Dutch people belonged to a kingdom and the Netherlands became twice as big.

            The union between the Dutch and Belgian people lasted for only fifteen years (1815-1830) and was difficult from the start. One of the main differences was that of religious denomination: Catholicism was dominant in the south, while the Dutch Republic built its system of values on protestant beliefs. King William I tried to create a ‘union complète et intime’, but his attempts were doomed to fail. In 1830 the Belgian Revolution broke out, during an opera performance in Brussels and in 1831 Leopold I was installed to the Belgian throne. William I refused to acknowledge Leopold as the legitimate ruler and tried to restore his power during the Ten Days Campaign (2-12 August 1831) but his attempt failed. In 1832 Belgian troops captured the citadel of Antwerp, which basically meant the final defeat of the Dutch. However, it took another seven years before William I officially acknowledged Belgium as an independent state.

            From 1830 and onwards Belgium and the Netherlands developed as separate states with different national heroes, anthems, and commemorations. On the Belgium side, the medieval knight Godfried van Bouillon, political leader Jacob van Artevelde, and the painter Rubens were celebrated. Hendrik Conscience published De Leeuw van Vlaanderen (The Lion of Flanders, 1838), a historical novel, which celebrated the bravery of Belgian forefathers during the Battle of the Golden Spurs (11 July 1302). Conscience, and many other authors, paved the way for the Flemish Movement, which strived for acknowledgement of Flemish language and culture.

            On the Dutch side, national sentiments were also increased by the depiction of great military victories of the past. Authors, intellectuals and painters especially turned to the Dutch Revolt and the Eighty Years War against Spain, which had led to the recognition of the Dutch Republic as an independent state. William of Orange was celebrated as the founding father of the nation, while sea heroes such as Piet Hein and Michiel de Ruyter were considered to be examples of bravery and loyalty. A contemporary hero was Jan van Speijk, who fought against the Belgian revolutionaries. Van Speijk let his ship explode on 5 February 1831 close to the harbour of Antwerp because he preferred to die instead of begin conquered by the Belgians. His last words became famous: ‘I prefer to go up in the air!’.

In 1840 king William I was succeeded by his son William II. In 1848 his power was reduced by the Constitutional Reform, which was designed by a commission under the supervision of Johan Rudolf Thorbecke. The ministers became responsible for government’s policies instead of the king. Compared to other European nations such as France and Germany, this was the outcome of a rather peaceful process of negotiations. The king was worried about the violent outbursts in foreign countries, and decided to install a committee which was appointed to develop a new constitution. In doing so, the king not only avoided popular revolts, but also secured the continuation of the monarchy. Only in the second half of the nineteenth century did various popular movements emerge, striving for catholic emancipation, abolitionism, socialist ideals and women’s rights.