Little of significance was added to literary criticism in the period between the fall of Rome in the fifith century and the great rediscovery of the classical past we know as the Renaissance (c 1300-1600 in Italy, though it was rather later in starting in France and England). The crucial development in this period was the adoptation of Christianity, and specifically the Christianity of the Church of Rome, as the universal religion of Western Europe. This made all the literature of the classical past automatically suspect, written as it was by pagans or outright atheists (though there were attempts to read some of it allegorically as obliquely relevant to Chrisitian truth; Virgil's1 'Fourth Eclogue' was credited with foretelling the birth of Christ, while his Aeneid was interpreted as an allegory of the soul's quest for salvation). St. Augustine2 was typical in this respect, ironically borrowing from the 'pagan' Plato's attacks on poetry in his City of God(after 410) to warn against the dangers of literature. The sole exception, of course, was the Bible (and the body of patristic, doctrinal and devotional writing which grew up around it). Only the clergy were allowed to interpret it, and they only within limits laid down by the hierarchy of the Church.
When the Renaissance came, literary criticism revived firstly in the efforts of writers such as Dante and Boccaccio to justify their own works, which were written in forms unknown to the classical arts. The novelty form was linked with the question of whether they should write in the vernacular (Italian, French, English) or in the 'universal' language, Latin. The Renaissance came bletadly to England, which was ravaged by dynastic squabbles known as the Wars of the Roses for most of the fifteenth century; then, when the arts seemed to be reviving at the Court of Henry VIII, it was thrown into confusion again by the Reformation. Only when a political and religious settlement was secured under Elizabeth I was culture, and literature in particular, able to flourish. Mid-way through her reign, England's literary Renaissance found its perfect spokesman in Sir Philip Sidney.
1Virgil (70-19BC) was the most respected of all Latin poets.
His Eclogues are pastoral poems on rural themes; his Georgics is a didactic on farming; and the Aeneid
is the epic which links tha fall of Troy with the founding of Rome through the person of the Trojan hero Aeneas.
2St Augustine of Hippo (AD354-430) was a leader of the early Christian church; not to be confused with the later St Augustine, first Archbishop of Canterbury.