Thus the timing--the unfortunate mistiming--of Regnans in Excelsis:
Accordingly one Nicholas Morton, sometime canon of York who had fled his homeland and was now a protégé of Goldwell in Rome, was sent secretly to England to consult the likes of Thomas Percy to discover how the proposed excommunication would be received; that is, whether it would be accompanied by an uprising.
Morton reported that it would be widely welcomed. Indeed, he had been begged to get immediate papal support for a revolt that was already being planned.
Exactly what happened next is, once again, unclear.
Pius did not act promptly (perhaps because he was engrossed in so many other urgent issues). So the two earls (Northumberland and Westmorland) who were to lead the 1569 rising wrote to him on its very eve, begging for his blessing. Pius replied with astonishing speed, promising to provide financial and spiritual aid and to declare Elizabeth a heretic. . . .
The rebellion was soon under way. It swept across northern England. Mass was said once again in Durham Cathedral. Thousands were joining in. Had not Elizabeth’s chief captain held York – and, more importantly, had the promised papal excommunication arrived – the rebellion could have surged southwards and probably toppled Elizabeth.
But inexplicably Pius had not yet delivered his bull. Why? We do not know. Not until February 10, 1570 – to observe due process (and no doubt believing that the rebellion was still alive) – did he take final evidence from 10 English residents in Rome to confirm Elizabeth’s guilt. At last, on February 25, the bull was released. And to enable it to be circulated faster, the bull itself authorised production of notarially attested copies anywhere.
Scarisbrick adds some commentary about Mary, Queen of Scots, who had come under Elizabeth I's protection (control) in 1568. I think he makes an error: Mary was married three times: to Francis of France, Lord Darnley of England, and James Bothwell of Scotland. Scarisbrick comments, giving Mary a fourth husband:
Nevertheless, he does bring up an interesting question: did Pope Pius V not want Mary, Queen of Scots on the throne of England in place of Elizabeth I?
Please read the rest there.