Nor was he insensible to the charms of art, especially those of poetry.

His favourite authors among the poets seem to have been Shakespeare, Milton, Scott, Wordsworth, and Cowper.

His knowledge of the customs and modes of thought of the natives of India, rarely equalled and never surpassed, was more than half the secret of his notable success as an administrator.

The greatest achievement of his busy and unselfish life was the suppression of the system of organized murder known as Thuggee, and in the execution of that prolonged and onerous task he displayed the most delicate tact, the keenest sagacity, and the highest power of organization.
His own words are his best epitaph: 'I have gone on quietly,' he writes, '"through evil and through good report", doing, to the best of my ability, the duties which it has pleased the Government of India, from time to time, to confide to me in the manner which appeared to me most conformable to its wishes and its honour, satisfied and grateful for the trust and confidence which enabled me to do so much good for the people, and to secure so much of their attachment and gratitude to their rulers.' [5] His grandson.

Captain J.L.Sleeman, who, when stationed in India from 1903 to 1908, visited the scenes of his grandfather's labours, states that everywhere he found the memory of his respected ancestor revered, and was given the assurance that no Englishman had ever understood the native of India so well, or removed so many oppressive evils as General Sir W.H.Sleeman, and that his memory would endure for ever in the Empire to which he devoted his life's work.
This necessarily meagre account of a life which deserves more ample commemoration may be fitly closed by a few words concerning the relatives and descendants of Sir William Sleeman.
His sister and regular correspondent, to whom he dedicated the _Rambles and Recollections_, was married to Captain Furse, R.N.
His brother's son James came out to India in 1827, joined the 73rd Regiment of the Bengal Army, was selected for employment in the Political Department, and was thus enabled to give valuable aid in the campaign against Thuggee.