Alexander, Margrave of Brandenburg-Ansbach  Christian Friedrich Carl Alexander (; 24 February 1736 – 5 January 1806) was the last margrave of the two Franconian principalities, Bayreuth and Ansbach, which he sold to the King of Prussia, a fellow member of the House of Hohenzollern. His parents were Charles William Frederick, Margrave of Brandenburg-Ansbach, and Friederike Luise of Prussia, daughter of King Frederick William I of Prussia, sister of Frederick II of Prussia, a granddaughter of the British King George I and niece of the reigning British King George II (who would die aged 77 and leave his grandson, Charles's second cousin, as King George III, when Charles was 24). After the sudden death of his elder brother Carl Frederick August on 9 May 1737, "Alexander", as he later called himself, became Crown Prince of the principality. From 1748 to 1759, he studied at Utrecht. As the young "Count of Sayn" (the county of Sayn-Altenkirchen in the Westerwald having been absorbed into the Principality of Ansbach in 1741) he travelled to Turin and Savoy. On 22 November 1754, in Coburg, Alexander married Princess Frederica Caroline of Saxe-Coburg-Saalfeld (1735–1791), daughter of Franz Josias, Duke of Saxe-Coburg-Saalfeld, and Anne Sophia, Princess of Schwarzburg-Rudolstadt. On 3 August 1757, Alexander became the Margrave of Brandenburg-Ansbach. The "Residenz" of the principality was at Ansbach, but Alexander preferred his hunting estate and country seat in Triesdorf. Here, he renovated the "White Castle" for his mistress Hippolyte Clairon, the "Red Castle" for himself, and built the "Villa Sandrina" for another mistress, "Fräulein Kurz", and the "Round Villa" ("Villa Rotunda") for his mistress (and later wife) Elizabeth Craven. In 1758, Alexander founded the porcelain factory in Ansbach and made ventures into agriculture by importing sheep. In 1769, he acquired the principality of Bayreuth pursuant to the "Haus- und Reichsgesetze" laws of the House of Hohenzollern. In 1780, Alexander founded his own bank, the "Hochfürstlich-Brandenburg-Anspach-Bayreuthische Hofbanco", out of which later came the "Bayerische Hypotheken- und Wechselbank" ("Bavarian Mortgage and Change Bank", today absorbed into the "HypoVereinsbank").