Answer:
by carrying on a violent feud
Explanation:
Montague and Capulet families were the feuding families who were against with each other. They were rival of each other since generations. Juliet was the daughter of Capulet and Romeo was the son of Montague. They fell in love for each other. It is because of the rivalry of their parents that the lovers died out of grief and impossibility of staying together. Every Montagues and the Capulets were at war each other and they stood against because of the dispute. The deaths of the lovers was majorly effected by the rivalry of the families.