External conflicts run throughout the drama of Romeo and Juliet, many of which involve those among members of the feuding families and Fate.
The opening scene of insults and aggressive acts between the servants of the houses of Montague and Capulet certainly signals the turbulent and violent tone that the drama will take in future scenes.
In the Prologue of Shakespeare's tragedy, the Chorus mentions that Romeo and Juliet are "star-crossed lovers," whose love is "death-marked." Surely Romeo's presence at the celebration of the Capulet's where Tybalt espies him marks Romeo for death as the enraged nephew of Lord Capulet accuses Romeo of mocking their celebratory occasion and says,
It fits when such a villain is a guest
I'll not endure him. (1.5)
In Act III Benvolio and Mercutio enter the square on a very hot day and encounter Tybalt, who aggressively insults them. Mercutio retaliates with insults. Then, Romeo arrives and tries to ameliorate the situation; however, his intervening allows Tybalt to reach around Romeo and fatally stab Mercutio. As he dies, Mercutio curses both the Capulets and Montagues:
...A plague o' both your houses!
They have made worms' meat of me. I have it,
And soundly too--your houses! (3.1.)
Lord Capulet's insistence that Juliet marry Paris causes conflict as Juliet refuses since she is already married to Romeo. She, then, appeals to Friar Lawrence who devises a plan that will give him time to speak with her parents and explain the marriage and love between Juliet and Romeo.
- Fate vs. Romeo and Juliet
After Romeo is banished from Verona, there is a plague in Mantua where he hides. The quarantine imposed upon Mantua prevents Romeo's learning that Juliet is not dead, so when Romeo's servant tells him that he has seen Juliet buried, Romeo believes her dead. In desperation he buys poison and visits her tomb where he kills himself. When Juliet finally awakens from the potion that Friar Lawrence has given her, she finds Romeo dead and commits suicide herself.