Short answers, pulled from the story.
The Holy Roman Empire was a polity that controlled much of Central and Western Europe, headed by the Holy Roman Emperor and marked by a decentralized political structure. It began in either 800 or 962 and lasted until its dissolution in 1806 during the Napoleonic Wars.
The Holy Roman Empire developed in the Early Middle Ages, beginning in either 800 or 962, and it lasted a millennium until 1806. Its dissolution came on the 6th of August 1806, when Emperor Francis II abdicated.
On the 25th of December 800, Pope Leo III crowned Charlemagne, the Frankish king, as Roman Emperor. The title lapsed by 924 and was revived in 962 when Pope John XII crowned Otto of Saxony, known as Otto the Great, as emperor.
A decree following the Diet of Cologne in 1512 changed the name to the Holy Roman Empire of the German Nation, a form first used in a document in 1474. The change coincided with the loss of imperial territories in Italy and Burgundy and the rising importance of the German Imperial Estates.
Voltaire remarked sardonically that the body called the Holy Roman Empire was "in no way holy, nor Roman, nor an empire." The quip has been quoted as a famous assessment of the empire's name and nature.
The imperial office was traditionally elected by a handful of prince-electors and electors-spiritual. The Golden Bull of 1356, issued by Charles IV, fixed the college of seven prince-electors and ruled that the emperor be chosen by a majority rather than unanimous consent.
For most of its history the empire covered the modern Czech Republic, Belgium, the Netherlands, Luxembourg, Liechtenstein, Monaco, Switzerland, Slovenia, Germany, and Austria, plus large parts of eastern France, northern and central Italy, and western Poland.