William I of Württemberg
William I (27 September 1781 – 25 June 1864) was King of Württemberg from 30 October 1816 until his death.
Upon William's accession, Württemberg was suffering crop failures and famine in the "Year Without a Summer", in 1816.
After taking office, he initiated sweeping reforms, resulting in the approval of the Estates of Württemberg to a constitution on September 25, 1819.
In his 48-year reign, the kingdom moved from one that was created from different denominational principalities and a heterogeneous agricultural country, into a constitutional state with a common identity and a well-organised management.
In addition to his successful domestic policy, he pursued throughout his reign an ambition focused on German and European foreign policy.
Alongside the great powers of Prussia and Austria, he imagined a third major German power in the form of Bavaria, Saxony, Hanover and Württemberg.
Although this plan never succeeded, it ensured a consistent, coherent and targeted policy during his reign.
William was the only German monarch who was forced to recognise the Frankfurt Constitution of 1848.
After the failure of the March Revolution of 1848, he pursued restorative policies that counteracted his liberal image from before the revolution.
He died in 1864 at Rosenstein Castle in Bad Cannstatt and is buried in the Württemberg Mausoleum.
Princess Catherine of Württemberg
Princess Catherine Frederica Charlotte of Württemberg (Stuttgart, 24 August 1821 – Stuttgart, 6 December 1898) was a daughter of William I of Württemberg and Pauline Therese of Württemberg.
She was the mother of William II of Württemberg.
Pauline Therese of Württemberg
Pauline of Württemberg (4 September 1800 – 10 March 1873) was a daughter of Duke Louis of Württemberg and Princess Henriette of Nassau-Weilburg.
She married her first cousin King William I of Württemberg and was his consort.
Christoph, Duke of Württemberg
Christoph of Württemberg, Duke of Württemberg (12 May 1515 – 28 December 1568) ruled as Duke of Württemberg from 1550 until his death in 1568.
Duke Eugen of Württemberg (1758–1822)
Duke Eugen of Württemberg( 21 November 1758 – 20 June 1822) was a German prince.
He was the brother of Frederick I of Württemberg
Prince Frederick of Württemberg
Prince" Frederick" Charles Augustus of Württemberg( 21 February 1808 – 9 May 1870) was a General in the Army of Württemberg and the father of William II of Württemberg.
Frederick was a member of the Royal Family of Württemberg and a Prince of Württemberg.
Princess Augusta of Württemberg
Princess Augusta of Württemberg( 4 October 1826 in Stuttgart – 3 December 1898, ibid.) was a daughter of King William I of Württemberg and his wife, Pauline of Württemberg.
Louis Frederick, Duke of Württemberg-Montbéliard
Louis Frederick of Württemberg- Montbéliard( 29 January 1586 in Montbéliard – 26 January 1631 in Montbéliard) was the founder of a cadet line of the House of Württemberg known as the Dukes of Württemberg- Montbéliard.
Louis Frederick of Württemberg was born at Montbéliard Castle as the fifth child and second son of Duke Frederick I of Württemberg, and princess Sibylla of Anhalt.
Wilhelm, Duke of Urach
Count Friedrich Wilhelm Alexander Ferdinand of Württemberg, 1st Duke of Urach( 6 July 1810, in Stuttgart – 17 July 1869, in Schloss Lichtenstein), was the son of Duke Wilhelm of Württemberg( 1761 – 1830), younger brother of King Frederick I of Württemberg, by his morganatic wife, Baroness Wilhelmine von Tunderfeldt- Rhodis( 1777 – 1822), who had married in 1800.
He was the first Head of the House of Urach.
Wilhelm served as a cavalry officer in the army of the then- independent Kingdom of Württemberg.
He also tested cannon for the Army of Württemberg, some of which can still be seen at Lichtenstein Castle, which he substantially rebuilt in the 1840s.
He was inspired by the romantic historical novel" Lichtenstein" by Wilhelm Hauff( 1826).
Hauff was in turn inspired by the works of Walter Scott.
He was created Duke of Urach on 28 March 1867, with the style of Serene Highness.
Wilhelm was a junior member of the royal family of Württemberg.
He was a nephew of King Frederick( d. 1816), and was a first cousin of King William I of Württemberg( ruled 1816 – 1864).
Barbara Sophie of Brandenburg
Barbara Sophia of Brandenburg (16 November 1584 – 13 February 1636) was duchess of Württemberg by marriage to Duke John Frederick of Württemberg and acted as regent of the Duchy of Württemberg for their minor son, Duke Eberhard III of Württemberg, in 1631-1633.
She was the daughter of the Catherine of Küstrin (1549–1602) and Elector of Joachim Frederick of Brandenburg.

Question: Where did Pauline Therese Of Württemberg's husband die?
Answer: Rosenstein Castle