The term ‘Bluestockings’ originated as a nickname for a group of 18th Century women headed by Elizabeth Montagu who met in each others' salons to further their education. The National Portrait Gallery in London is currently holding a major exhibition to celebrate these cultivated women. As part of our series looking at bluestocking women, Anna McNamee went to the gallery to find out about the historian Catherine Macaulay and her often scandalous life.