Final answer:
Much of Charlemagne's empire was located between the lines of latitude encompassing northern Spain and Bohemia, in the region that would later include parts of Germany, Italy, and France.
Step-by-step explanation:
Charlemagne's empire, which was at its height from the late 8th century to the early 9th century, was primarily located between the lines of latitude that today correspond to northern Spain and Bohemia, the present-day Czech Republic. This vast territory spanned central parts of Europe and included what would later be known as Germany, Italy, and parts of France and the Low Countries. The latitude lines give us a rough estimate; however, the actual empire's boundaries fluctuated due to various military campaigns and political changes.
As Charlemagne's realm emerged, it encompassed various kingdoms, such as the Kingdom of Italy, the Kingdom of Germany, and the Kingdom of Burgundy, as well as the Kingdom of Bohemia, all under the umbrella of the Holy Roman Empire. Charlemagne's efforts made him a pivotal figure in European history by reviving the concept of a united Europe under a Christian state, which incorporated diverse Germanic kingdoms and sought to continue the legacy of the Roman Empire.