Polidori, John William, 1795-1821 (Oxford Reference)—

English-Italian writer, physician, son of Gaetano Polidori and uncle to Dante Gabriel and Christina Rossetti. Some consider John Polidori as the creator of modern vampire fiction with his work "The Vampyre." John Polidori was Lord Byron's personal physician and participated in the famous ghost story competition in Geneva which resulted in Mary Shelley's Frankenstein. Inadequately financially supported by his writing or medical career and suffering from debt and depression, Polidori committed suicide in 1821.

Plutarch (Library of Congress Name Authority)—

Greek historian, essayist, biographer, philosopher, and priest, living from roughly 46-119 C.E. Plutarch's works heavily influenced the development of the biography, the essay, and historical writing in Europe from the 16th to 19th centuries. He is best known for his Parallel Lives, a set of biographies of eminent Greeks and Romans, as well as his Moralia, a collection of essays on ethical, political, religious, physical, and literary subjects.

Plautus, Titus Maccius (Library of Congress Name Authority)—

Roman comic dramatist living from 245-184 B.C.E., known simply as "Plautus." Plautus' comedies, strongly influenced by Greek theatre, are the earliest complete works of Latin literature which have survived. Although Plautus' writing has been widely criticized by scholars, his works remained influential long after his death, influencing such literary figures as Shakespeare and Molière.

Pitt, William, 1759-1806 (Library of Congress Name Authority)—

Known as "Pitt the Younger" to distinguish him from his father, Pitt the Elder. Pitt was a British Prime Minister from 1783 to 1801, again resuming office from 1804 to 1806. Pitt orchestrated the Acts of Union 1800 which united Great Britain and the Kingdom of Ireland into the United Kingdom. His tenure was characterized by the occurrences of the French Revolution and Napoleonic wars. Pitt was a major catalyst in strengthening the office of prime minister, generally regarded as an efficient and reform-oriented politician.