500
"...A lioness hath whelped in the streets; And graves have yawn'd, and yielded up their dead; Fierce fiery warriors fight upon the clouds, In ranks and squadrons and right form of war, Which drizzled blood upon the Capitol; The noise of battle hurtled in the air, Horses did neigh and dying men did groan, And ghosts did shriek and squeal about the streets."
What is Calpurnia's dream?