Foreshadowing details in the prologue include the mention of an "ancient grudge" and a "new mutiny," which suggests a long-standing feud between the two households and the possibility of a violent conflict. Additionally, the phrase "civil blood makes civil hands unclean" hints at a tragedy involving death and bloodshed.
The central conflict revealed in the prologue is the intense feud between the two households, which has led to a breakdown of peace and harmony in Verona.
The event foreshadowed in the prologue is the tragic death of the "star-cross'd lovers," who take their own lives in order to end the strife between their families.