Early modern period
In the early modern period, the Holy Roman Empire was a union of territories in Central Europe under a Holy Roman Emperor the first of which was Otto I. The last was Francis II, who abdicated and dissolved the Empire in 1806 during the Napoleonic Wars. Despite its name, for much of its history the Empire did not include Rome within its borders.
List of Imperial Diet participants (1792)
The Holy Roman Empire was a highly decentralized state for most of its history, composed of hundreds of smaller states, most of which operated with some degree of independent sovereignty. Although in the earlier part of the Middle Ages, under the Salian and Hohenstaufen emperors, it was relatively centralized, as time went on the Emperor lost more and more power to the Princes. The membership of the Imperial Diet in 1792, late in the Empire's history but before the beginning of the French Revolutionary Wars, gives some insight as to the composition of the Holy Roman Empire at that time.