What started World War 1?
Many historians consider the assassination of Archduke Franz Ferdinand of Austria the start of World War 1. Soon after the assassination Austria declared war on Serbia. Within four weeks their allies declared war on one another.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: What started World War 1?
### Input: 
### Response: Many historians consider the assassination of Archduke Franz Ferdinand of Austria the start of World War 1. Soon after the assassination Austria declared war on Serbia. Within four weeks their allies declared war on one another.