Quechua is an Amerind language with about 8 million people in Bolivia, Peru, Ecuador, Colombia and Argentina. Quechua was the language of the Inca empire which was destroyed by the Spanish in the 16th century. The Inca used a system of knotted strings known as quipu to send messages around their empire. The number and shape of the knots and the colours of the strings helped to remind messengers of the contents of the messages. Recent research suggests that the quipu might have been used not just as mnemonic devices but also to record the Quechua language phonetically. Quechua first appeared in print in 1560 in the form of a dictionary by Domingo de Santo Tomás. Other early texts include collections of hymns by Cristóbal de Molina and a Quechua cathechism by Juardo Palomino.