[1][2] It was at its peak intensity under Emperor Xiaowen of the Northern Wei dynasty in 496.
[2] To formalize sinification, a number of actions were taken prior to the name changes.
Later, after the division of Northern Wei into two in 534, the paramount general of Western Wei, Yuwen Tai, tried to reverse these name changes and restore Xianbei names.
A number of generals and officials changed their names back to Xianbei names, but after the collapse of Western Wei, the regent Yang Jian near the end of Northern Zhou permanently restored the use of Han names for both Han and Xianbei alike.
As a compromise, there were some exceptions, for example, the clan of Emperor Wen of Sui's wife Empress Dugu kept their Xianbei name of Dugu and did not once again change the name into Liu.