Question

Austria-Hungary declared war on Serbia. Explain how this led to the conflict becoming the Great War.​

Answer 1

When Austria-Hungary declared war on Serbia, it led to Russia declaring war on Austria-Hungary as well because Russia was in an alliance with Serbia.

Germany which had an alliance with Austria-Hungary via the Triple Alliance then declared war on Russia.

Russia was already in an alliance with Great Britain and France known as the Triple Entente and when Germany declared war on Russia, Great Britain and France declared war on Germany.

Thus began the Great War.