Final answer:
The Plan of St. Gall is associated with the Carolingian era, a period of cultural revival in Europe that spanned roughly from the 8th to the 9th century, aimed at regaining the classical wisdom and aesthetics of Roman antiquity.
Step-by-step explanation:
The period we associate with the Plan of St. Gall is the Carolingian era. This era is renowned for its cultural and intellectual revival, significantly under the reign of Charlemagne and his successors. The Plan of St. Gall is a famous architectural drawing from the early 9th century, which represents a monastic compound according to the ideals of the time and reveals the vision for organization and structure in monastic life. It is one of the most precious documents of Carolingian art and architecture because it provides valuable insight into the design and function of a Benedictine monastery. Innovations in architecture and other forms of Carolingian art during this period were part of an attempt to recreate and emulate a classical Roman aesthetic, which was seen as a golden age of European culture.
During the Carolingian period, the revival extended through modern-day France, Switzerland, Germany, and Austria. Examples such as the Palatine Chapel in Aachen, which was heavily influenced by classical models, showcase the period's distinctive architectural approach. The Carolingian renaissance was not just limited to architecture but was also evident in manuscript illuminations, sculpture, and other forms of religious art which were produced exclusively for the emperor's court and the high officials of the Church.