Where was Romeo banished to after he killed Tybalt?

After the well-meaning, but "star-crossed" Romeo, who is newly wed to his beloved Juliet, appears on the scene of the public place where the contentious exchange of Mercutio and Tybalt is in progress. He seeks to intervene and diffuse the tension between Juliet's cousin and his friend, but fate enters. For, despite Romeo's well-meaning words,

I do protest I never injured thee,
But love thee better than thou canst devise
Till thou shalt know the reason of my love
And so, good Capulet--which name I tender
As dearly as mine own--be satisfied. (3.1)

Tybalt feels insulted, believing that Romeo mocks him. So, he reaches around Romeo and fatally stabs Mercutio. Incensed that Tybalt would kill his beloved Mercutio, Romeo rashly attacks Juliet's cousin and kills him. Then, realizing what has just happened, Romeo cries out, "O I am fortune's fool!" And, he flees to the cell of Friar Laurence. There, the priest tells Romeo to calm himself; further, he instructs Romeo to 

Go get thee to thy love....
But look thou stay not till the watch he set,
For then thou canst not pass to Mantua,
Where thou shalt live till we can find a time
To blaze [make public] your marriage. (3.3)

Friar Laurence instructs Romeo to hide in Mantua, and he will locate Romeo's servant and send messages through him. Unfortunately, while Romeo is in this city a plague breaks out and the city is quarantined, so Balthasar, Romeo's servant, cannot communicate with him. Consequently, Romeo does not learn about what happens with Juliet.