The technique of enamelling was introduced to the Indian subcontinent in the late sixteenth century, when craftsmen from the court of the Mughal emperor Akbar (r.1556–1605) were sent to learn from European craftsmen based in Portuguese Goa. Coloured glass is fused to metal at very high temperatures, to create a decorative and hardwearing outer layer. By the time of the Prince's tour in 1875, enamel production had been established in several centres in north India, such as Jaipur, Delhi, Lucknow, Benares and Sindh, each one developing its own styles and colour palettes.