| Clue | Source | Date |
|---|---|---|
| Archduke ____’s assassination in 1914 prompted Austria-Hungary to declare war on Serbia | The Times Specialist Sunday | 25 Mar 2018 |
| His assassination sparked W.W. I | New York Times | 30 Jun 2017 |
| His assassination sparked W.W. I | ||
| Pre-World War I archduke |