Definition: 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.
Input: In 1870, after France attacked Prussia, Prussia and its new allies in Southern Germany (among them Bavaria) were victorious in the Franco-Prussian War. It created the German Empire in 1871 as a German nation-state, effectively excluding the multi-ethnic Austrian Habsburg monarchy and Liechtenstein. Integrating the Austrians nevertheless remained a strong desire for many people of Germany and Austria, especially among the liberals, the social democrats and also the Catholics who were a minority within the Protestant Germany.
Output:
When did France attack Prussia?