This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

After the fall of Napoleon, not only was Napoleonic Code retained by conquered countries including the Netherlands, Belgium, parts of Italy and Germany, but has been used as the basis of certain parts of law outside Europe including the Dominican Republic, the US state of Louisiana and the Canadian province of Quebec. The memory of Napoleon in Poland is favorable, for his support for independence and opposition to Russia, his legal code, the abolition of serfdom, and the introduction of modern middle class bureaucracies.
After the fall of Napoleon, many countries retained what system of law?