What started the 1st world war
- What was the 1st world war about
- What ended the 1st world war
- What triggered the 1st world war
- What cause the 1st world war
- What country started the 1st world war
- What caused the 1st world war
- What sparked the 1st world war
- What 1st world war was fought at sea
- What 1st world war battle was fought at sea