The history of Modern India began when the country became an independent nation within the British commonwealth on 15 August, An example of secondary source is CA Bayly's by Illustrated history of Modern India. Secondary sources involve analysis, synthesis, interpretation, or evaluation of primary sources. Examples of secondary sources are journal articles that comment on or analyse research, textbooks, dictionaries and encyclopedias, books that interpret, analyse, political commentary, biographies, dissertations, newspaper editorial/opinion pieces, criticism of literature, art works or music and so on.