Constantijn of the Netherlands

William I (1772 to 1843) was the first King of the Netherlands and the founder of the Dutch monarchy. Born in The Hague as the son of William V, the last stadtholder of the Dutch Republic, he fought against the French invasion of 1795 and then spent nearly two decades in exile in Britain and Prussia. He returned in 1813 as sovereign prince and was proclaimed king in 1815, ruling Luxembourg as grand duke at the same time. Nicknamed the Merchant King for the canals, shipping lines and industry he financed, he lost the southern provinces in the Belgian Revolution of 1830 and abdicated in 1840 in favour of his son William II. With his wife and first cousin Wilhelmina of Prussia he was the ancestor of every Dutch monarch since.

William II (1792 to 1849) was King of the Netherlands and Grand Duke of Luxembourg from 1840 until his death. Born in The Hague and educated in Berlin and at Oxford, he made his name as a soldier, serving under Wellington in Spain and commanding Dutch and Belgian troops at the Battle of Waterloo in 1815, where he was wounded. As Prince of Orange he tried and failed to hold the southern provinces during the Belgian Revolution of 1830. Succeeding his father William I in 1840, he is remembered above all for accepting in 1848 the liberal constitution drafted by Johan Rudolph Thorbecke, which moved real power to parliament and shaped the modern Dutch monarchy. He married Anna Pavlovna of Russia, a sister of two tsars.

Prince Frederick of the Netherlands (1797 to 1881) was the second son of King William I and Wilhelmina of Prussia and a career soldier in both Dutch and Prussian service. Born in Berlin during his family's exile, he rose to field marshal, commanded the Dutch forces in the Ten Days' Campaign against Belgium in 1831 and was for decades the senior military figure of the young kingdom. He served as Grand Master of Dutch freemasonry for more than sixty years and was a well known patron of charities, schools and the arts. In 1825 he married Princess Louise of Prussia. A younger brother of King William II, he died at Wassenaar in 1881.

Princess Marianne of the Netherlands (1810 to 1883) was the youngest daughter of King William I and Wilhelmina of Prussia and a sister of King William II. Born in Berlin while her family was in exile, she married Prince Albert of Prussia in 1830; the marriage ended in separation and divorce, which cost her her standing at the Prussian court and kept her away from Berlin for the rest of her life. She bought the Reinhartshausen estate in the Rhine valley and built a great palace at Kamenz in Prussian Silesia, becoming known as a collector of paintings and as a builder of churches, schools and roads for the districts she owned. She died in the Rhineland in 1883.

William III (1817 to 1890) was King of the Netherlands and Grand Duke of Luxembourg from 1849 until his death. Born in Brussels to King William II and Anna Pavlovna of Russia, he resented the constitutional limits his father had accepted in 1848 and clashed repeatedly with his ministers across a long reign in which slavery was abolished in the Dutch colonies, the railways spread and the country industrialised. His attempt to sell Luxembourg to France touched off the international crisis of 1867. After his first wife Sophie of Wurttemberg and all three of their sons had died, he married Emma of Waldeck and Pyrmont in 1879, and their only child Wilhelmina succeeded him in 1890.

Princess Sophie of the Netherlands (1824 to 1897) was the only surviving daughter of King William II and Anna Pavlovna of Russia and a sister of King William III. Born in The Hague, she married Carl Alexander, the future Grand Duke of Saxe-Weimar-Eisenach, in 1842 and spent the rest of her life in Germany as his consort. She was a serious patron of music and scholarship in a Weimar still living on its literary reputation, and when Goethe's last grandson left the poet's papers to her she founded the Goethe Archive there in 1885, the institution that grew into the Goethe and Schiller Archive. She died in Weimar in 1897.

Wilhelmina (1880 to 1962) was Queen of the Netherlands from 1890 to 1948 and the longest reigning Dutch monarch. The only child of King William III and Emma of Waldeck and Pyrmont, she came to the throne at the age of ten under her mother's regency and was inaugurated in her own right in 1898. She held the Netherlands to neutrality through the First World War and made the monarchy a byword for stubborn independence. When Germany invaded in May 1940 she escaped to London, where she led the government in exile and spoke to the occupied country over Radio Oranje, becoming the voice of Dutch resistance. She returned in 1945, abdicated in favour of her daughter Juliana in 1948 and died at Het Loo in 1962.

Princess Irene of the Netherlands (born 1939) is the second daughter of Queen Juliana and Prince Bernhard and a younger sister of Princess Beatrix. Born at Soestdijk Palace, she set off a constitutional storm in 1964 when her conversion to Roman Catholicism and her marriage to Carlos Hugo, Duke of Parma, the Carlist claimant to the Spanish throne, went ahead without the approval of parliament, costing her her place in the line of succession. She spent years at her husband's side in Spanish politics before the marriage ended in 1981. Since then she has worked as a writer and campaigner on nature and the human relationship with it, founding the NatuurCollege foundation in 1995.

Princess Margriet of the Netherlands (born 1943) is the third daughter of Queen Juliana and Prince Bernhard. She was born in Ottawa during her family's wartime exile, in a hospital room declared Dutch territory for the occasion so that she would hold her mother's nationality alone, and the tulips Canada receives from the Netherlands every year date from that stay. She married the jurist Pieter van Vollenhoven in 1967 and they have four sons. For decades one of the busiest working members of the royal family, she has been closely identified with the Netherlands Red Cross and the International Federation of Red Cross and Red Crescent Societies, and with equestrian and veterans' causes.

Catharina-Amalia, Princess of Orange (born 2003) is the heir apparent to the Dutch throne and the eldest daughter of King Willem-Alexander and Queen Maxima. Born in The Hague, she took the title Princess of Orange, traditionally held by the heir, when her father became king in 2013. She attended the Sorghvliet gymnasium in The Hague, declined the royal allowance due to her when she turned eighteen because she was still a student, and went on to read politics, psychology, law and economics at the University of Amsterdam after a year abroad. She is the eldest of three sisters, with Princess Alexia and Princess Ariane, and a direct descendant of William I, the first Dutch king.

Princess Alexia of the Netherlands (born 2005) is the second daughter of King Willem-Alexander and Queen Maxima and stands second in line to the Dutch throne, after her elder sister Catharina-Amalia. Born in Amsterdam, she grew up at Villa Eikenhorst in Wassenaar and later at Huis ten Bosch Palace in The Hague, went to Dutch schools and then completed the international baccalaureate at UWC Atlantic College in Wales, before going on to university study in the United Kingdom. She appears with her parents and sisters at national occasions such as King's Day and the state opening of the Dutch parliamentary year, but holds no official duties of her own.