What event is considered the start of world war 1
- What event triggered the start of world war 1
- What event is considered the start of world war ii in september 1939
- What event is considered the beginning of world war 1
- What event is considered the spark of world war 1
- What was the event that sparked the start of world war 1
- What event is considered the immediate cause of world war 1
- What event marked the start of world war 1
- What event caused the start of world war 1
- Which event is often considered the start of world war 1
- What event led to the start of world war 1
- What event is generally considered the cause of world war 1
- What event directly triggered the start of world war 1
- What event marked what is now considered the start of world war ii in 1939
- What single event triggered the start of world war 1
- What event is often considered the immediate cause of world war 1