Pius V.had not merely excommunicated her, which was a barren and ineffective threat, a telum imbelle sine ictu; he had also purported to depose her as a heretic, and to release her subjects from the duty of allegiance.
Another Vicar of Christ, Gregory XIII., went farther.

He intimated, not obscurely, that whosoever removed such a monster from the world would be doing God's service.

This at least was no idle menace.
Those great leaders of Protestantism in Europe, Coligny, Murray, William the Silent, were successively murdered within a few years.
That was, as Fra Paolo said when he saw the dagger (stilus) which had wounded him, the style (stylus) of the Roman Court.

It is all very well to say that Gregory was a blasphemous, murderous old bigot, and might have been left to the God of justice and mercy, who would deal with him in His own good time.

Before that time came, Elizabeth might have been in her grave, Mary Stuart might have been on the English throne, and the liberties of England might have been as the liberties of Spain.
Elizabeth never felt personal fear.