Question

Which European counrty enetered World War 1 as part of the central powers but later switched sides to the Allies in 1915?

Answer 1

The Kingdom of Italy was an ally of the Central Powers (German
Empire, Austria-Hungarian Empire) at the outbreak of World War One
in August 1914. As a member of "Triple Alliance" their allegiance
was intended to counter-balance the Triple Entente allegiance of
France, United Kingdom and Russia. However, at the outbreak of
hostilities, the Kingdom of Italy did not join in fighting and
instead joined the allied (France, Russia, United Kingdom) side in
May 1915.