Simpson travelled in India, Tibet and Kashmir between 1858 and 1861, intending to produce drawings for a sumptuous 3 volume work on India to be published by Day & Son. The scheme never materialised as Day & Son went into bankruptcy, but a more modest volume, India Ancient and Modern, a series of Illustrations of the Country and People, including one-fifth of his drawings, already made as plates, with a text by Sir John W. Kaye was published in 1867. Two hundred of Simpson's original drawings from the tour were exhibited in 1864 ('Watercolour Drawings of India, Thibet and Cashmere') at the German Gallery, 168 New Bond Street, a further fifty drawings were exhibited in 1866, and one hundred and eighty-nine were shown at the Pall Mall Galleries, 48 Pall Mall in 1869.
Leh is the Buddhist capital in North India. The capital of Ladakh, situated in the eastern parts of Jammu and Kashmir, it was the seat of the Ladakhi royal family in the 17th century until their exile in the 1830s. At 11,000 ft., on the banks of the Indus, it was a busy market on the Silk route, on the Khardung La - Karakoran corridor into China.