Fate
I think that fate is the most important reason for the tragedy of Romeo and Juliet. This i think because at the the time it was written many people believed mostly in fate and believed it to be the reason for most happenings. Firstly i believe it was apparent when the servant who was giving out the invitations for Capulets party asked Romeo and Benvolio to help him. The servant could have asked anyone and he even invited him to the party for their help after. Romeo references to his belief in fate when saying "some consequence yet hanging in the stars" foreshadowing the meeting of Juliet. Also fate is responsible for the reason for the death of the young lovers because: If Capulet had not organised the wedding of Count Paris and Juliet so early, Juliet would not have rushed into drinking the 'death' potion.
Also fate is blamed upon the fact that Friar Lawrence's letter did not reach Romeo in time meaning he was not informed of their plan. Another time fate appears is the fact Romeo kills himself just before Juliet wakes up where as if it had been delayed then Juliet would have woken to tell him.
The death of Romeo and Juliet also brings a large change in the ancient grudge of the families where they are united in grief. Their death could have been for the greater good of Verona which is where fate linked in to another of the main concepts of the play: death.