Short answers, pulled from the story.
Nicholas Sanders (c. 1530-1581) was an English Catholic priest, polemicist, and exile who wrote De origine ac progressu schismatis Anglicani, a foundational text for Catholic histories of the English Reformation. He also participated in the Second Desmond Rebellion, landing at Smerwick harbour in Ireland with a force of around 600 soldiers in an attempt to challenge Elizabethan rule.
Nicholas Sanders is believed to have died of cold and starvation in the spring of 1581 in the south-west of Ireland. After the massacre at Smerwick in November 1580, he fled into the hills and spent months as a fugitive before his death.
The Siege of Smerwick was a three-day engagement in November 1580 in which the Irish Royal Army under Arthur Grey, the 14th Baron Grey de Wilton, massacred the foreign troops who had landed at Smerwick harbour as part of the Second Desmond Rebellion. Sanders had helped organise and accompany that landing force of around 600 Spanish and Italian soldiers with covert Papal support; he escaped the massacre by fleeing into the Irish hills.
De origine ac progressu schismatis Anglicani is Sanders' major unfinished work on the English Reformation, which became the basis for later Catholic histories and martyrology of the period. It was continued after his death by Edward Rishton and printed supposedly at Cologne in 1585, though actually produced by Jean Foigny at Reims; subsequent editions involved editing by William Allen and work attributed to Robert Persons.
Nicholas Sanders was educated at Winchester College and New College, Oxford, where he was elected fellow in 1548 and graduated Bachelor of Civil Law in 1551. At the age of ten he had first been sent as a student to Hyde Abbey.
Protestant reactions included Peter Heylin dismissing Sanders with the nickname "Dr Slanders." Gilbert Burnet was prompted by Sanders' account to write his own History of the Reformation at the end of the seventeenth century.