Complex sentence: Queen dowager Mary of Guise, acting as regent for her daughter Mary, Queen of Scots, wanted to crush the Protestants and felt the use force would be necessary civil war appeared imminent, but each side shrank from the first step.
Split into simpler sentences: Queen dowager Mary of Guise, acting as regent for her daughter Mary, Queen of Scots, wanted to crush the Protestants and felt the use of force would be necessary. Civil war appeared imminent, but each side shrank from the first step.