Margrave Frederick William of Brandenburg-Schwedt (1715–1744)
Frederick William of Brandenburg- Schwedt( 18 March 1715 – 12 September 1744 in Prague) was a Prussian Major General and commander of the Guards on Foot.
He was the son of Margrave Albert Frederick of Brandenburg- Schwedt and his wife Maria Dorothea of Courland( 1684- 1743).
In his lifetime he held the courtesy title of Margrave of Brandenburg.
His first cousin of the same name( Frederick William) was of the senior line and held the town and lands of Schwedt.
Princess Anna Elisabeth Louise of Brandenburg-Schwedt
Princess and Margravine Anna Elisabeth Louise of Brandenburg- Schwedt( 22 April 1738 – 10 February 1820) was a Prussian princess.
She was a daughter of Margrave Frederick William of Brandenburg- Schwedt and his wife, Princess Sophia Dorothea of Prussia.
Henrietta Maria of Brandenburg-Schwedt
Henriette Maria of Brandenburg- Schwedt( 2 March 1702 probably in Berlin – 7 May 1782 in Köpenick), was a granddaughter of the" Great Elector" Frederick William of Brandenburg.
She was the daughter of Philip William, Margrave of Brandenburg- Schwedt( 1669- 1711), the eldest son of the elector's second marriage with Sophia Dorothea of Schleswig- Holstein- Sonderburg- Glücksburg.
Her mother was Johanna Charlotte( 1682- 1750), the daughter of Prince John George II, Prince of Anhalt- Dessau.
Charles Frederick Albert, Margrave of Brandenburg-Schwedt
Karl Friedrich Albrecht, Margrave of Brandenburg-Schwedt (10 June 1705 – 22 June 1762), a grandson of Frederick William of Brandenburg ("the Great Elector") and son of Margrave Albert Frederick of Brandenburg-Schwedt, was a Prussian military officer and the "Herrenmeister" (grand master) of the Order of Saint John (Bailiwick of Brandenburg).
Charles of Brandenburg-Schwedt was born in Berlin.
He joined the Prussian Army at an early age and distinguished himself during the First Silesian War at the capture of Głogów, at the Battle of Mollwitz and the Battle of Chotusitz.
He took command in Upper Silesia in the spring of 1745, to the special satisfaction of his cousin, King Frederick II of Prussia.
During the Seven Years' War Margrave Charles again held independent commands, as Frederick II had confidence in him, and he distinguished himself at the Battle of Hochkirch and the Battle of Torgau.
In both battles, as at Mollwitz, he was wounded.
The General German Biography (ADB) describes him as a noble, philanthropic character and lover of the arts and sciences.
For 31 years he governed the knights, the Bailiwick of Brandenburg, and its fiefs as Grand Master of the Order of St. John, having been installed at Sonnenburg in 1731.
He died in Breslau.
Margravine Philippine of Brandenburg-Schwedt
Margravine Philippine Auguste Amalie of Brandenburg-Schwedt (10 October 1745 – 1 May 1800) was a Landgravine consort of Hesse-Kassel by marriage to Frederick II, Landgrave of Hesse-Cassel.
Frederick William, Margrave of Brandenburg-Schwedt
Frederick William of Brandenburg- Schwedt( 17 November 1700 – 4 March 1771) was a German nobleman.
In his lifetime, from 1711 to 1771, he held the titles Prince in Prussia and Margrave of Brandenburg, with the style Royal Highness.
He was made a knight of the Order of the Black Eagle.
In the 19th century he was retrospectively known by the title Margrave of Brandenburg- Schwedt, in order to differentiate his branch of the Hohenzollern dynasty.
He was the second owner of the Prussian secundogeniture of Brandenburg- Schwedt.
His parents were Philip William, Margrave of Brandenburg- Schwedt, and Princess Johanna Charlotte of Anhalt- Dessau.
He was the nephew of King Frederick I of Prussia.
Marie Amalie of Brandenburg
Maria Amalia of Brandenburg- Schwedt( 26 November 1670 in Cölln – 17 November 1739 at Bertholdsburg Castle in Schleusingen) was a princess from the Brandenburg- Schwedt line of the House of Hohenzollern and by marriage a Duchess of Saxe- Zeitz.
Frederick II, Landgrave of Hesse-Kassel
Frederick II
(14 August 1720 – 31 October 1785) was Landgrave of Hesse-Kassel (or Hesse-Cassel) from 1760 to 1785.
He ruled as an enlightened despot, and raised money by renting soldiers (called "Hessians") to Great Britain to help fight the American Revolutionary War.
He combined Enlightenment ideas with Christian values, cameralist plans for central control of the economy, and a militaristic approach toward international diplomacy.
Frederick Henry, Margrave of Brandenburg-Schwedt
Frederick Henry, Margrave of Brandenburg- Schwedt( 21 August 1709, in Schwedt – 12 December 1788, in Schwedt) was the last owner of the Prussian secundogeniture of Brandenburg- Schwedt.
His father was Margrave Philip William; his mother was Charlotte Johanna, a daughter of Prince John George II of Anhalt- Dessau and Princess Henriette Catherine of Nassau.
Charles Philip of Brandenburg-Schwedt
Margrave Charles Philip of Brandenburg-Schwedt (5 January 1673 in Sparnberg – 23 July 1695 in Casale Monferrato) was a Hohenzollern prince and a titular Margrave of Brandenburg-Schwedt.
Near the end of his life he became Grand Master of the Order of Saint John (Bailiwick of Brandenburg).

Question: When did Margravine Philippine Of Brandenburg-Schwedt's husband die?
Answer: 31 October 1785