The "Dark Ages" is a historical periodization traditionally referring to the Middle Ages (c. 5th–15th century) that asserts that a demographic, cultural, and economic deterioration occurred in Western Europe following the decline of the Roman Empire.

The term employs traditional light-versus-darkness imagery to contrast the era's "darkness" (lack of records) with earlier and later periods of "light" (abundance of records).[3] The concept of a "Dark Age" originated in the 1330s with the Italian scholar Petrarch, who regarded the post-Roman centuries as "dark" compared to the "light" of classical antiquity. The phrase "Dark Age" itself derives from the Latin saeculum obscurum, originally applied by Caesar Baronius in 1602 to a tumultuous period in the 10th and 11th centuries. The concept thus came to characterize the entire Middle Ages as a time of intellectual darkness in Europe between the fall of Rome and the Renaissance; this became especially popular during the 18th-century Age of Enlightenment.

As the accomplishments of the era came to be better understood in the 19th and 20th centuries, scholars began restricting the "Dark Ages" appellation to the Early Middle Ages (c. 5th–10th century), and now scholars also reject its usage in this period.[9] The majority of modern scholars avoid the term altogether due to its negative connotations, finding it misleading and inaccurate. Petrarch's pejorative meaning remains in use, typically in popular culture which often mischaracterises the Middle Ages as a time of violence and backwardness.

The idea of a Dark Age originated with the Tuscan scholar Petrarch in the 1330s. Writing of the past, he said: "Amidst the errors there shone forth men of genius; no less keen were their eyes, although they were surrounded by darkness and dense gloom".

From his perspective on the Italian peninsula, Petrarch saw the Roman period and classical antiquity as an expression of greatness. He spent much of his time traveling through Europe, rediscovering and republishing classic Latin and Greek texts. He wanted to restore the Latin language to its former purity. Renaissance humanists saw the preceding 900 years as a time of stagnation, with history unfolding not along the religious outline of Saint Augustine's Six Ages of the World, but in cultural (or secular) terms through progressive development of classical ideals, literature, and art.

Petrarch wrote that history had two periods: the classic period of Greeks and Romans, followed by a time of darkness in which he saw himself living. In around 1343, in the conclusion of his epic Africa, he wrote: "My fate is to live among varied and confusing storms. But for you perhaps, if as I hope and wish you will live long after me, there will follow a better age.

Enlightenment
During the Age of Enlightenment of the 17th and 18th centuries, many critical thinkers saw religion as antithetical to reason. For them the Middle Ages, or "Age of Faith", was therefore the opposite of the Age of Reason.Baruch Spinoza, Fontenelle, Kant, Hume, Thomas Jefferson, Thomas Paine, Denis Diderot, Voltaire, Marquis De Sade and Rousseau were vocal in attacking the Middle Ages as a period of social regress dominated by religion, while Gibbon in The History of the Decline and Fall of the Roman Empire expressed contempt for the "rubbish of the Dark Ages".[31] Yet just as Petrarch, seeing himself at the cusp of a "new age", was criticising the centuries before his own time, so too were Enlightenment writers.

Consequently, an evolution had occurred in at least three ways. Petrarch's original metaphor of light versus dark has expanded over time, implicitly at least. Even if later humanists no longer saw themselves living in a dark age, their times were still not light enough for 18th-century writers who saw themselves as living in the real Age of Enlightenment, while the period to be condemned stretched to include what we now call Early Modern times. Additionally, Petrarch's metaphor of darkness, which he used mainly to deplore what he saw as a lack of secular achievement, was sharpened to take on a more explicitly anti-religious and anti-clerical meaning.

Nevertheless, the term 'Middle Ages' was in general use before the 18th century to denote the period before the Renaissance. The earliest recorded use of the English word "medieval" was in 1827. The concept of the Dark Ages was also in use, but by the 18th century it tended to be confined to the earlier part of this period. The earliest entry for a capitalized "Dark Ages" in the Oxford English Dictionary is a reference in Henry Thomas Buckle's History of Civilization in England in 1857. Starting and ending dates varied: the Dark Ages were considered by some to start in 410, by others in 476 when there was no longer an emperor in Rome, and to end about 800, at the time of the Carolingian Renaissance under Charlemagne, or alternatively to extend through to the end of the 1st millennium.