Question: When did Frances Vane, Marchioness Of Londonderry's husband die?

Knowledge 1: Frances Vane, Marchioness of Londonderry
Frances Anne Vane, Marchioness of Londonderry (17 January 1800 – 20 January 1865) was a wealthy English heiress and noblewoman.She was the daughter of Sir Henry Vane-Tempest, 2nd Baronet.She married Charles William Stewart, 1st Baron Stewart, who changed his surname to hers and became Charles William Vane.She became Marchioness in 1822 when Charles succeeded his half-brother as 3rd Marquess of Londonderry.Through her daughter Frances Anne, she is the great-grandmother of Winston Churchill. [SEP] Knowledge 2: Charles Vane, 3rd Marquess of Londonderry
Charles William Vane, 3rd Marquess of Londonderry (born Charles William Stewart; 1778–1854) was an Irish soldier in the British army, a politician, and a nobleman.As a soldier he fought in the French Revolutionary Wars, in the suppression of the Irish Rebellion of 1798, and in the Napoleonic wars.He excelled as a cavalry commander on the Iberian Peninsula under John Moore and Arthur Wellesley (later the Duke of Wellington).Having been dismissed by Wellington, his half-brother Lord Castlereagh helped him to launch a diplomatic career.He was posted to Berlin in 1813, and then as Ambassador to Austria, where his half-brother was the British plenipotentiary at the Congress of Vienna.He married Lady Catherine Bligh in 1804 andthen Lady Frances Anne Vane, a rich heiress, in 1819, changing his surname to hers, thus being called Charles Vane instead of Charles Stewart from there on.He succeeded his half-brother as 3rd Marquess of Londonderry in 1822.He was made a Knight of the Garter in 1853, and died a year later in London on 6 March 1854.
Knowledge 1: Frances Vane, Marchioness of Londonderry
Frances Anne Vane, Marchioness of Londonderry (17 January 1800 – 20 January 1865) was a wealthy English heiress and noblewoman.She was the daughter of Sir Henry Vane-Tempest, 2nd Baronet.She married Charles William Stewart, 1st Baron Stewart, who changed his surname to hers and became Charles William Vane.She became Marchioness in 1822 when Charles succeeded his half-brother as 3rd Marquess of Londonderry.Through her daughter Frances Anne, she is the great-grandmother of Winston Churchill. [SEP] Knowledge 2: Lord Adolphus Vane-Tempest
Lord Adolphus Frederick Charles William Vane-Tempest (2 July 1825 – 11 June 1864), known until 1854 as Lord Adolphus Vane, was a Conservative Party politician in the United Kingdom.He was the fourth child (and second son) of Charles Vane, 3rd Marquess of Londonderry and his wife Frances Anne Vane, Marchioness of Londonderry.In December 1852, he was elected at a by-election as Member of Parliament (MP) for the City of Durham, but the election was overturned on petition the next year.In 1854 he was elected unopposed to the House of Commons as MP for North Durham after the death of his father, filling the seat vacated by his elder brother George Vane-Tempest, Viscount Seaham, who succeeded to the peerage as Earl Vane.He held the seat until his death in 1864, aged 38.
During the enthusiasm for the Volunteer Movement in 1859–60, although his brothers were connected with the 2nd (Seaham) Durham Artillery Volunteer Corps formed at the family's Seaham Colliery, Lord Adolphus raised and commanded an infantry corps, the Sunderland Rifles.According to Anne Isba, author and Victorian Studies scholar, Vane was "notoriously unstable" and was "described by Queen Victoria as having 'a natural tendency to madness.'Vane, who on one occasion violently attacked his wife and infant son, died four years later during a struggle with four keepers."
Knowledge 1: Charles Vane, 3rd Marquess of Londonderry
Charles William Vane, 3rd Marquess of Londonderry (born Charles William Stewart; 1778–1854) was an Irish soldier in the British army, a politician, and a nobleman.As a soldier he fought in the French Revolutionary Wars, in the suppression of the Irish Rebellion of 1798, and in the Napoleonic wars.He excelled as a cavalry commander on the Iberian Peninsula under John Moore and Arthur Wellesley (later the Duke of Wellington).Having been dismissed by Wellington, his half-brother Lord Castlereagh helped him to launch a diplomatic career.He was posted to Berlin in 1813, and then as Ambassador to Austria, where his half-brother was the British plenipotentiary at the Congress of Vienna.He married Lady Catherine Bligh in 1804 andthen Lady Frances Anne Vane, a rich heiress, in 1819, changing his surname to hers, thus being called Charles Vane instead of Charles Stewart from there on.He succeeded his half-brother as 3rd Marquess of Londonderry in 1822.He was made a Knight of the Garter in 1853, and died a year later in London on 6 March 1854. [SEP] Knowledge 2: Lord Adolphus Vane-Tempest
Lord Adolphus Frederick Charles William Vane-Tempest (2 July 1825 – 11 June 1864), known until 1854 as Lord Adolphus Vane, was a Conservative Party politician in the United Kingdom.He was the fourth child (and second son) of Charles Vane, 3rd Marquess of Londonderry and his wife Frances Anne Vane, Marchioness of Londonderry.In December 1852, he was elected at a by-election as Member of Parliament (MP) for the City of Durham, but the election was overturned on petition the next year.In 1854 he was elected unopposed to the House of Commons as MP for North Durham after the death of his father, filling the seat vacated by his elder brother George Vane-Tempest, Viscount Seaham, who succeeded to the peerage as Earl Vane.He held the seat until his death in 1864, aged 38.
During the enthusiasm for the Volunteer Movement in 1859–60, although his brothers were connected with the 2nd (Seaham) Durham Artillery Volunteer Corps formed at the family's Seaham Colliery, Lord Adolphus raised and commanded an infantry corps, the Sunderland Rifles.According to Anne Isba, author and Victorian Studies scholar, Vane was "notoriously unstable" and was "described by Queen Victoria as having 'a natural tendency to madness.'Vane, who on one occasion violently attacked his wife and infant son, died four years later during a struggle with four keepers."

Answer: 6 March 1854