This is because after winning independent slave trade also was in that event, or because Europeans wanted to influence Christians into Africa.
The answer is yes. The Greco-Roman legal tradition continue to have a strong positive influence on modern law and society. They greatly influenced the modern world with the creation of laws, development of democratic government practices, influences in languages, literature, arts, infrastructure, and city planning.
It codified several branches of law, including commercial and criminal law, and divided civil law into categories of property and family. The Napoleonic Code made the authority of men over their families stronger, deprived women of any individual rights, and reduced the rights of illegitimate children.