In the 1830s the British Empire was firmly entrenched in India, but by 1837 Lord Palmerston and John Hobhouse, fearing the instability of Afghanistan, the Sindh, and the increasing power of the Sikh kingdom to the north, raised the spectre of a possible Russian invasion of India through Afghanistan. The Russian empire was slowly extending its domain into central Asia, and this was seen as an encroachment south that might prove fatal for the British Company rule in India. The British sent an envoy to Kabul to form an alliance with Afghanistan's Emir Dost Mohammad Khan against Russia.