Born into a humble family, Pepys was appointed about 1659 as a clerk in the office of the Exchequer, where on January 1st 1660, he began the diary for which he is chiefly known. He steadily improved his position, in time becoming secretary of the Admiralty, a member of Parliament, president of the Royal Society, trusted confidant of Charles II and James II; and friend of the great scholars of his age.
His diary (published in 1825), which he kept through 1669, presents a fascinating picture of the official and upper-class life in Restoration London, with vivid, honest accounts of ordinary as well as great events, including the Plague and the Great Fire of London.
Pepys died in London on May 26th, 1703.
 Encyclopedia Britannica.