The family name at the time was Wesley, not Wellesley. Arthur's
eldest brother (there were two elder — Richard, William (later
Wellesley-Pole) and and an elder sister, Anne, followed by Henry
and Gerald Valerian. The grand father was Richard Colley (or
Cowley or Cooley — which would be most applicable in eighteenth-
century Ireland? Despite this the family preferred the
Anglicized version Colley). The name Wellesley was adopted by
Richard (Arthur's eldest brother) when in search of Marquessate.
Afetr service as Governor General of India, he became Marquis
Wellesley ignoring the Mornington, because he thought it
reflected a genealogy back to Norman, which the Cooleys didn't
have. James, L. The Iron Duke: a military biography of
Wellington. London, 1992. Longford, E. The Years of the Sword.
London, 1969. The late Lady Longford (who married Frank, later
Lord, Longford and had access to family archives and those of HM
the Queen and the Dutch royal family - Kitty Wellington, wife of
1st Duke, m 1807, was a daughter