Question

Who were the first two countries to declare war? Why?

Answer 1

Austria-Hungary Vs Serbia

Step-by-step explanation:

Austria-Hungary made first declaration of war against Serbia because of assassination of the Austrian Prince Francis Ferdinand and his wife Sophia on June 28, 1914.

Answer 2

Austria-Hungary Vs Serbia

Step-by-step explanation:

Austria-Hungary made first declaration of war against Serbia because of assassination of the Austrian Prince Francis Ferdinand and his wife Sophia on June 28, 1914.