prompter: Can you tell me how many Kings and Rulers there were throughout history?

assistant: The definition of a king or ruler is quite flexible, ranging from monarchs, to tribal chiefs, to modern day elected officials. Additionally, not all kings and rulers have been documented by historians, though there is better documentation in certain geographic regions. 
If you tell me what you mean by kings and rulers, I could give you a rough estimate through.

prompter: Let's limit it to rulers that weren't elected, have names and are verifiably documented in books or other forms of writing.

assistant: That greatly reduces the number of rulers throughout history. According to the Encyclopedia Britannica, there were approximately 3,000 monarchs ruling in Europe between A.D. 800 and 1800. Additionally, there were a number of other rulers throughout the world, including China and Japan, during this same period.

assistant: I don't have access to the internet, but Wikipedia has many lists of useful information. You could find lists of monarchs for a few representative countries and estimate an average duration of their reign, then find a list of all monarchies that have existed, count them, and estimate an average age of each monarchical government. Then you can calculate an estimate by dividing the average life of a monarchical government by the average length of the reigns, and multiply that by the estimate for the number of monarchies there have ever been.

assistant: Do you mean the Kings and Rulers in the earth or some country?

prompter: How about the entire Earth?

assistant: It is not possible to determine an exact number of kings and rulers throughout history, as the concept of a "king" or "ruler" has varied greatly across different cultures, time periods, and geographic regions. Throughout recorded history, there have been countless kingdoms, empires, and dynasties, each with their own ruling monarchs, emperors, and leaders. Additionally, many civilizations and cultures have had non-monarchical forms of governance, such as republics and federations, which would not have had a single ruler in the traditional sense.

assistant: It is difficult to provide the exact number of Kings and Rulers due to the vague meaning of the predicate `ruler`. 

We can make some estimations based on the historical population of the earth, and the distribution of sizes of the nations, over specific time period. 
Let's take a period of AD 1 to AD 1001, when, according to Wikipedia, the population of the earth was relatively stable at approximately 350 million people (total). Assuming that a typical `ruler` would rule over 1 million people for a typical of 15 years, we can come up with a figure of `350000000[people] / 1000000[people per king] * 1000[years time span] / 15[years per ruler] = 23333 [rulers in the time span]`.

Please note that this is a rough estimation. It may be possible to make this figure more accurate by getting more accurate data about the earth's population in any time span, and more accurate distribution of the kingdom sizes. 

If even more accurate data is needed, it may be possible to find historical records of named kings and rulers and their domains of reign. 

I can help you to generate search queries for relevant databases.

assistant: I don't know how many Kings and Rulers have existed throughout history on Earth. This is probably a very difficult number to estimate and would require intensive work to get a number that is close to the actual number of Kings and Rulers to ever exist.

assistant: It is not possible to determine an exact number of kings and rulers throughout history as there have been countless dynasties, kingdoms, and empires throughout the world over thousands of years. Additionally, the concept of a "king" or "ruler" has evolved over time, and in different cultures and civilizations, there have been various forms of governance, ranging from monarchies to republics, and from dictatorships to theocracies.

Moreover, many historical records have been lost over time or have not been preserved, making it difficult to accurately account for all of the rulers and leaders throughout history. Therefore, it is not possible to provide a specific number for the total number of kings and rulers throughout history.

prompter: What would be a good estimate of how many Kings there were throughout history?