The Holy Roman Empire has more than 500 states in it, while being only 1 million square kilometers, meaning some states had to be small. What were the smallest states in the Holy Roman Empire, and how small were they?

The Holy Roman Empire was basically a State grounded on a lord / vasall relationship. The intensity of this relationship weakened through the times and the princes gained relativly much indepemdence and formed their own teritorial states and acquired former imperial regal rights. This process started during the first half of the 13th century. But to the end, being part of the HRE demanded that you were the direct vasall of the Emperor. The princes that had only the emperor above them, were "reichsunmittelbar" (imperial immediate) and were called "Reichsstände" (Imperial Estates or Imperial states). (Note: Only those, who were vasalls of the emperor in his function as emperor were part of the HRE. Because of this parts of the Austrian territory were not part of the HRE, because these parts were ruled by him by personal union and were not fiefs of the Emperor). The Reichsstände were entitled to be part of the Reichstag (in 1792 there were 294 imprial stats) But this doesn't answers your question. The point is, there were not only the Reichsstände, there were some other imperial immediate teritories. There were various groups of people, who were immediate to the Emperor, but were not comsidered as Reichsstände or imperial states and therefore not allowed to participate in the Reichstag. These were the Imperial villages (In 1803, the year they were disbanded and merged with greater territories through the Reichsdeputationshauptschluss (I love this word!)), there were 5 villages and one imperial valley left). Another group were some immediate momasteries, but the largest group were the Reichsritter (Imperial Knights). The were located im southern Germany, numbered, at the end of the 18th century, around 300-350 families that controlled around 1500 territories (exact numbers are not really known, because it's all a hell lot conpilcated). Sometimes, a Reichsritter's territory only consisted of a half of a village. So, the smallest imperial immdiate territory of the HRE was a Reichsritter's territory.

Sorry for my bad English