Bernhard Karlgren

Klas Bernhard Johannes Karlgren (; 15 October 1889 – 20 October 1978) was a Swedish sinologist and linguist who pioneered the study of Chinese historical phonology using modern comparative methods. In the early 20th century, Karlgren conducted large surveys of the varieties of Chinese and studied historical information on rhyming in ancient Chinese poetry, then used them to create the first ever complete reconstructions of what are now called Middle Chinese and Old Chinese. Provided by Wikipedia