Well without full context I would assume Trench Warfare because thats what 3 1/2 of the 4 year wars where full of.
He legally recognized Christianity
Answer:
US OPEN 1999
Explanation:
In 1999, Serena Williams won her first Grand Slam...
2 years, 11 months, 26 days before Leylah Fernandez was born
3 years, 2 months, 2 days before Emma Raducanu was born