In 1840, Sándor Kőrösi Csoma arrived in Darjeeling, hoping that he would be able to trace the origin of the Magyar ethnic group, but died before he was able to enter Tibet. In 1865 Great Britain secretly began mapping Tibet. Trained Indian surveyor-spies disguised as pilgrims or traders, called pundits, counted their strides on their travels across Tibet and took readings at night.