Samuel Pepys PRS was an English diarist and naval administrator. He served as administrator of the Navy of England and Member of Parliament and is most famous for the diary he kept for a decade while still a young man. Pepys had no maritime experience, but he rose to be the Chief Secretary to the Admiralty under both King Charles II and King James II through patronage, diligence, and his talent for administration. His influence and reforms at the Admiralty were important in the early professionalisation of the Royal Navy.
The detailed private diary that Pepys kept from 1660 until 1669 was first published in the 19th century and is one of the most important primary sources for the English Restoration period. It provides a combination of personal revelation and eyewitness accounts of great events, such as the Great Plague of London, the Second Dutch War, and the Great Fire of London.