The family name is something stable to identify a person.
In the world there a different systems to give a family name to a person.
There are limits on changing your family name, as it should remain possible to identify a person. Governments have the power to refuse the wish of a citizen to change his family name out of this perspective accouding to the European Court of Human Rights in 2004.
In some countries persons have been forced to change their family name. This has been the case in Belgian Congo after the takeover of power by mobutu, who found that names should be africanised. The European Court of Human Rights has the opinion in 2004 that forcing individuals to change their faimly name is an intrusion into the private life of citizens by the government.
You can find out more about this matter on the international law forum in the following countries: