Lou 娄 is listed 139th in the Song dynasty classic text Hundred Family Surnames.

This source of Lou began around 400 BC, and is a branch of Si, the ducal surname of Qi.

This source of Lou began around 300 BC, and is a branch of Cao, the surname of the ruling clan of Zhulou.

[3] During the Xianbei Northern Wei dynasty, Emperor Xiaowen (reigned 467–499 AD) implemented a drastic policy of sinicization, ordering his own people to adopt Chinese surnames.

The Pilou 匹娄, Yilou 伊娄, and Yinalou 乙那娄 tribes of Xianbei adopted Lou 娄 as their surname.