Short answers, pulled from the story.
The Rising of the North, also called the Revolt of the Northern Earls, was an unsuccessful Catholic rebellion in 1569 against Queen Elizabeth I. The rebels sought to depose Elizabeth and replace her with Mary, Queen of Scots, in order to restore Roman Catholicism to England.
The rebellion was led by Charles Neville, 6th Earl of Westmorland, and Thomas Percy, 7th Earl of Northumberland. They assembled roughly six thousand men and occupied Durham before being routed by royal forces in December 1569.
The Earl of Northumberland fled into Scotland after the rebels dispersed. He was captured by James Douglas, 4th Earl of Morton, and handed over to Elizabeth I in 1572. Elizabeth had him beheaded at York.
Elizabeth I demanded at least seven hundred executions and declared martial law across the Yorkshire Dales. Approximately six hundred supporters of Mary, Queen of Scots, were executed, and a contemporary account noted the victims were almost entirely ordinary working people.
Pope Pius V issued the papal bull Regnans in Excelsis in 1570, excommunicating Elizabeth I and declaring her deposed in an attempt to support the rebellion. The document arrived only after the rebellion had already been suppressed, and it ultimately gave Elizabeth greater justification for viewing English Catholics with suspicion.
After the rebellion was crushed, Mary remained in English custody. Elizabeth I eventually brought her to trial for treason in 1587. Mary was convicted and executed.