Korean: there are three Chinese
characters for the surname Ku. The most common of the three
claims thirty-two clans, but only two can be documented. The other two
Ku surnames each have one clan, with its own Chinese character. All
four of the Ku clans immigrated from China. The clans that use the
more common character came in two waves: the first settled in the
Nungsong sometime before 945, and the second, which settled in
Ch’angwon, arrived in 1224. The name of the immigrant who founded
the first of these two clans has been lost; but the name of the second
is Ku Chon-yu. Members of these two clans can be found throughout the
Korean peninsula, but 45 percent of them live in Kyongsang South
province, while 20 percent of them live in Seoul and Kyonggi
province. The founder of the clan that uses the other Ku character was
named Ku T’ae-rim. He was an emissary for Tang China on his way to
Japan when a storm blew his ship onto the shores of Koguryo Korea
in 663. He settled in Koguryo territory and subsequently held a
post in that government. Koguryo was a Korean kingdom which existed
in the northern part of the Korean peninsula from 37 bc to
ad 668. Its territory was incorporated into Shilla when the
peninsula was unified in 668. Most of the modern-day members of this
clan live in Ch’ungch’ong province. Very little is known of the
origins of the clan which uses the third Ku character. There are only
a few families which still use this character in Korea; they live in
Kyongsang province and Kangwon province.
Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4