Cecilie of Mecklenburg-Schwerin

Louise Henriette of Nassau was Electress of Brandenburg as the first wife of Frederick William, the Great Elector, whom she married in 1646. A daughter of Frederick Henry, Prince of Orange, and Amalia of Solms-Braunfels, she was raised in the Dutch Republic and brought Netherlandish ideas of land drainage, agriculture and garden design to the sandy country around Berlin. The town of Oranienburg, where she rebuilt a country residence, is named after her family. She wrote hymns in the German Reformed tradition, several of which stayed in use long after her death. Of her children, Frederick I survived to become the first King in Prussia, making her the ancestress of the Prussian royal line. She died in 1667 at the age of thirty nine.

Frederick I was the first King in Prussia, reigning from 1701 until 1713, having succeeded his father the Great Elector as Elector Frederick III of Brandenburg in 1688. Born at Koenigsberg, he negotiated the Crown Treaty with Emperor Leopold I, promising Prussian troops for the War of the Spanish Succession in exchange for recognition of a royal title, and crowned himself at Koenigsberg on 18 January 1701. His court at Berlin was lavish by Prussian standards. He founded the Academy of Arts and, with his wife Sophia Charlotte of Hanover, the Academy of Sciences, and he built the palace of Charlottenburg. His son Frederick William I and grandson Frederick the Great both reacted against his taste for ceremony and expense.

Frederick William I, called the Soldier King, was King in Prussia and Elector of Brandenburg from 1713 until 1740. Born in Berlin, the son of Frederick I and Sophia Charlotte of Hanover, he dismantled his father's expensive court, reorganised the administration into the General Directory, introduced compulsory primary schooling and left his heir the best drilled army in Europe together with a full treasury. He was known for his regiment of unusually tall soldiers and for the harsh discipline he imposed on his eldest son, the future Frederick the Great, whose attempt to flee Prussia in 1730 ended in a court martial. With his wife Sophia Dorothea of Hanover he had fourteen children, among them a king of Prussia and a queen of Sweden.

Wilhelmine of Prussia was Margravine of Brandenburg-Bayreuth and the eldest sister of Frederick the Great, to whom she remained unusually close all her life. Born in Berlin in 1709 to Frederick William I and Sophia Dorothea of Hanover, she married Frederick, Margrave of Brandenburg-Bayreuth, in 1731 after her mother's plan for a marriage into the British royal family collapsed. At Bayreuth she became a notable patron and builder, responsible for the Hermitage and the Margravial Opera House, and she composed music of her own. Her memoirs are the frankest surviving account of life at her father's court and a principal source for her brother's youth. She died in 1758 during the Seven Years' War.

Frederick II, known as Frederick the Great, was King in Prussia from 1740 and King of Prussia from 1772 until his death in 1786, and is the most celebrated member of the House of Hohenzollern. Born in Berlin to Frederick William I and Sophia Dorothea of Hanover, he survived a famously brutal upbringing before turning Prussia into a European great power. He seized Silesia from Maria Theresa in the War of the Austrian Succession, held it against Austria, France and Russia through the Seven Years' War, and gained Polish territory in the First Partition of 1772. He was also a flute player and composer, a correspondent of Voltaire, the builder of Sanssouci at Potsdam and the author of the Anti-Machiavel. His marriage to Elisabeth Christine of Brunswick produced no children, so the crown passed to his nephew Frederick William II.

Frederick William II was King of Prussia from 1786 until 1797, succeeding his uncle Frederick the Great, who had no children. Born in Berlin in 1744, the son of Prince Augustus William and Luise Amalie of Brunswick-Wolfenbuettel, he relaxed his uncle's austere regime, ended the state monopolies on coffee and tobacco, and spent generously on music and architecture. The Brandenburg Gate was built in his reign, and he was a competent cellist to whom Ludwig van Beethoven dedicated the two cello sonatas of his Opus 5. In policy he was less successful, intervening against revolutionary France, accepting the separate peace of Basel in 1795, and taking part in the Second and Third Partitions of Poland. His eldest son succeeded him as Frederick William III.

Frederick William III was King of Prussia from 1797 until 1840, through the years of Prussia's collapse before Napoleon and its recovery. Born at Potsdam in 1770, he married Louise of Mecklenburg-Strelitz in 1793, and the couple became unusually popular. His attempt at neutrality ended in the catastrophic defeats at Jena and Auerstedt in 1806 and the Treaty of Tilsit, after which he backed the reforms of Stein, Hardenberg, Scharnhorst and Humboldt that rebuilt the Prussian state, army and university system. He joined the alliance that defeated Napoleon between 1813 and 1815 and gained the Rhineland at the Congress of Vienna. In 1817 he merged the Lutheran and Reformed congregations into the Prussian Union of churches. Two of his sons, Frederick William IV and Wilhelm I, succeeded him in turn.

Frederick William IV was King of Prussia from 1840 until 1861, the eldest son of Frederick William III and Queen Louise. Born in Berlin in 1795, he was a gifted draughtsman with a passion for architecture who worked closely with Karl Friedrich Schinkel and Friedrich August Stueler on the building of Potsdam and Berlin, and who pressed for the completion of Cologne Cathedral. Romantic and conservative by temperament, he was overtaken by the revolution of 1848: he conceded a constitution but refused the imperial crown offered to him by the Frankfurt Parliament in 1849, calling it a crown from the gutter. From 1857 he was unable to govern, and his brother Wilhelm acted as regent before succeeding him. His marriage to Elisabeth Ludovika of Bavaria was childless.

Wilhelm I was King of Prussia from 1861 and the first German Emperor from 1871 until his death in 1888. Born in Berlin in 1797, the second son of Frederick William III and Queen Louise, he fought in the campaigns against Napoleon, commanded the troops that put down the Baden rising of 1849, and became regent in 1858 for his incapacitated brother Frederick William IV. As king he resolved a constitutional crisis over army reform by appointing Otto von Bismarck minister president in 1862, and under Bismarck's direction Prussia defeated Denmark, Austria and France in turn. He was proclaimed German Emperor in the Hall of Mirrors at Versailles on 18 January 1871, accepting with reluctance a title he felt diminished the Prussian crown. With Augusta of Saxe-Weimar-Eisenach he was the father of Frederick III.

Frederick III was German Emperor and King of Prussia for ninety nine days in 1888, the shortest reign in the history of his house. Born at Potsdam in 1831, the only son of Wilhelm I and Augusta of Saxe-Weimar-Eisenach, he studied at Bonn, commanded armies with distinction at Koeniggraetz in 1866 and at Woerth and Sedan in 1870, and was created crown prince of the new empire in 1871. With his wife Victoria, the eldest daughter of Queen Victoria, he favoured liberal parliamentary government on the British model, which set him at odds with Otto von Bismarck throughout his father's long reign. He was already seriously unwell when he finally succeeded in March 1888, and he died at Potsdam in June, leaving the throne to his eldest son, Wilhelm II.

Wilhelm II was the last German Emperor and King of Prussia, reigning from 1888 until his abdication in 1918. Born in Berlin in 1859, the eldest son of Frederick III and Victoria, Princess Royal, he was a grandson of both Wilhelm I and Queen Victoria. He dismissed Otto von Bismarck in 1890 and pursued a personal and assertive foreign policy, building a battle fleet that antagonised Britain and backing Austria-Hungary in the crisis of July 1914. His impulsive speeches and interviews repeatedly embarrassed his own governments, and by the later years of the First World War real authority had passed to the army command. He abdicated in November 1918 and spent the rest of his life at Doorn in the Netherlands, where he died in 1941. With Augusta Victoria he had six sons and one daughter.