Consider the question. People began to be alarmed. Samuel Pepys, who had an important position at the Admiralty, stayed in London and provided a contemporary account of the plague through his diary. On 30 April he wrote: "Great fears of the sickness here in the City it being said that two or three houses are already shut up. God preserve us all!" Another source of information on the time is a fictional account, A Journal of the Plague Year, which was written by Daniel Defoe and published in 1722. He had been only six when the plague struck but made use of his family's recollections (his uncle was a saddler in East London and his father a butcher in Cripplegate), interviews with survivors and sight of such official records as were available.

Whose diary describes the great plague of london?
 If the answer is 'Samuel Pepys'; explain the reasoning:
The relevant information to answer the above question is: Samuel Pepys, who had an important position at the Admiralty, stayed in London and provided a contemporary account of the plague through his diary.