BENGAL AND INDIA SECRET LETTERS, also known as Letters received from India and Bengal or merely Secret Letters to the Secret Committee, preserved at the India Office Library, London. This correspondence is arranged in two series : the first covers the period 1778-1859 and the second 1817-1857. Relevant Enclosures to Secret Letters on the events and matters of India policy, from 1778 to 1859, are huge in bulk-over 20, 000 bound volumes. Some of these Secret Letters have been printed in the Blue Books, presented to British Parliament, viz. Shāh Zamān's apprehended invasion of India-1806-XV (11) ; Afghanistan-1839-XI, XXV (30); Sind-1843-XXXIV; and the Sikh Wars-1846, XXI.

        The letters of 1804 throw light on the transactions of Lake and Ochterlony in the cis-Sutlej region, and those of 1805 on Holkar's intrusion into the Punjab. As the British interest increased in the affairs of the Sikhs, the Secret Letters became more detailed, especially about Shāh Zamān's invasion of the Punjab and the first British mission to the Sikh court (1798); the Metcalfe Mission to Lahore (1808); the imagined Sikh-Marāṭhā intrigues (1810); and the warlike preparations of Raṇjīt Siṅgh. The Enclosures to this correspondence include important documents such as Metcalfe's Minute on the British policy towards the Sikh-Scindīa tangle (1830); Trevelyan's report on the Indus Navigation Scheme (1831), and the Ropar meeting between Lord William Bentinck and Mahārājā Raṇjīt Siṅgh (1831). Secret Letters of later period deal with Auckland's policy towards Afghanistan and the Sikhs (1838), Punjab affairs and the Sikh co-operation during the first Anglo-Afghān war (1841-42). A number of letters written during the years 1842-44 describe the uncertain political state in Lahore. Events leading to the Anglo-Sikh war of 1845-46, and the details of military operations at Mudkī, Baddovāl, 'Alīwāl and Sabhrāoṅ are given (1846). They also give an account of Lāl Siṅgh's administration and the rebellion in Kashmīr which led to the treaty of Bharovāl. A full account of the uprisings at Multān and Hāzārā and particulars of the military operations against Multān, besides the actions at Chelīāṅvālā and Gujrāt are also provided (1848 and 1849).

B. J. Hasrat