23 JANUARY 1982, Page 16

Londonderry heirs

Sir: I hope I may be allowed to join issue with my old parliamentary colleague Enoch Powell when he states in his review of R. F. Foster's life of Lord Randolph Churchill (9 January) his suspicion that `the streak of abnormality which surfaced in successive generations of the Londonderrys may have been transmitted to him and through him from his Stewart mother', who married the seventh Duke of Marlborough, and that this may account for Randolph's 'erratic and unstable' behaviour `to an extent bordering on mania'. (My italics.) With the exception of the Duchess of Marlborough's own generation of Stewarts, strictly speak- ing Vane-Tempest-Stewarts, no abnor- mality has hitherto been recorded in any other generation of the Londonderry family. It is true that the Duchess's father's elder half-brother, the second Marquess, better known by his courtesy title of Lord Castlereagh, committed suicide in 1822 as the result of overwork and possibly also blackmail. In other words, he had a ner- vous breakdown. Except for the last week or so of his life, he had never behaved in the least abnormally throughout the ten years he was Foreign Secretary and Leader of the House of Commons and earlier when he was War Minister and held other important official posts. Castlereagh was the only son of the first Marquess by his first wife and died childless, while the members of his father's large family by his second wife were all quite normal. The Duchess's 'half-brother Frederick, the fourth Marquess, was a good consti- tuency member of the House of Commons, who by a coincidence represented the con- stituency for which Mr Powell now sits, besides serving as a junior minister and also being an adventurous traveller who wrote entertainingly of his travels. Unfortunately the last ten years of his life were clouded by mental illness and he too died childless. Ad- mittedly the Duchess's full brother Lord Adolphus Vane did behave abnormally, although he fought in the Crimean War and was decorated twice for his gallantry, which may have had some connection with his subsequent behaviour. The Duchess's other two brothers and her two sisters all lived quite normal lives. As one who possesses considerable knowledge of the Londonderry family and the family archives, I can confidently assert that it is only two members of one genera- tion, Fanny Duchess of Marlborough's and not successive generations which have shown signs of abnormality.

H. Montgomery Hyde

Westwell House, Tenterden, Kent