How does this theory explain the reigns of these kings lasting thousands or even tens of thousands of years? What is the relationship with the lifespan of the Anunnaki?

Okay, let's talk about this fascinating topic. This question hits right on a classic point in the "Ancient Astronaut Theory," and I'll try to explain it in plain language.

About the "Super-Long Reigns" in the Sumerian King List and the Lifespans of the Anunnaki...

Whoa, that's hitting the nail on the head! Many people are stunned the first time they see the ridiculously long reigns recorded in the Sumerian King List. Tens of thousands of years? That's longer than our entire known human civilization. Mainstream historians, of course, dismiss this as mythology. But if you look at it from the perspective of the Anunnaki theory, it actually presents a logically consistent explanation.

Let's break down how this theory explains it step by step.

1. Core Explanation: The Earliest Kings Weren't "Human" at All

The most straightforward explanation of this theory is: Those "kings" on the King List who ruled for tens of thousands of years weren't Earthlings as we understand them today; they were the Anunnaki themselves.

What are the Anunnaki? According to theories like those of Zecharia Sitchin, the Anunnaki are an alien race from a planet called Nibiru. They came to Earth to mine gold (supposedly to repair their home planet's atmosphere).
Kings as "Gods": To the primitive Earthlings of that time, these Anunnaki leaders possessed superhuman powers, advanced technology, and extremely long lifespans – they were essentially "gods." Therefore, the first "kings who descended from heaven" recorded by the Sumerians were actually the highest-ranking officials of these Anunnaki colonies (cities) established on Earth.

Think of it like this: Imagine an alien who lives for 5,000 years becoming the leader of a primitive tribe where the average lifespan is only 30 years. During his reign, generations upon generations of humans in the tribe might have lived and died – perhaps a hundred generations. But in the historical record, this leader's reign genuinely lasted thousands of years. To the people of that time, this was utterly incomprehensible, leading them to revere him as a god.

2. Key Question: Why Could the Anunnaki Live So Long?

This touches on another core premise of the theory – Nibiru's orbital period.

Time is Relative: The theory proposes that Nibiru has an extremely large orbit, taking approximately 3,600 Earth years to complete one revolution around the sun.
A "God's Year": For the Anunnaki, one of their years (on their home planet) equals 3,600 of our years. The Sumerians called this time unit a "Sar" (Shar).
Lifespan Conversion: So, if an Anunnaki lived to be 100 "years" old (Nibiru years), converted to Earth years that would be 100 * 3,600 = 360,000 years. Suddenly, those reigns of 20,000 or 30,000 years in the Sumerian King List might represent only about 5.5 to 8.3 "Nibiru years" of rule from the Anunnaki perspective. That sounds much more reasonable.

Their longevity is relative to us Earthlings. From their own viewpoint, their lifespans are normal.

3. Evolution: Why Did Later Kings' Reigns Get Shorter?

This is where the theory gets really interesting, as it explains a very clear trend in the Sumerian King List: After the Great Flood, the reigns of kings drastically shortened, becoming closer and closer to normal human lifespans.

The theory explains it like this:

Pre-Flood (The Age of the Gods): The rulers were pure-blooded Anunnaki with extremely long lifespans, hence reigns measured in "tens of thousands of years."
Post-Flood (The Age of Demi-Gods): The Great Flood was a turning point. After the flood, the Anunnaki began interbreeding with the humans they had created (like the "sons of God" in the Bible who saw the "daughters of men" and took them as wives), producing offspring.
Dilution of Bloodline: These offspring were "demi-gods" (Demigods). They inherited some of the Anunnaki longevity genes, but their bloodline was diluted. Consequently, their lifespans were much shorter than pure-blooded Anunnaki, though still significantly longer than ordinary humans. For example, Gilgamesh, the first king after the flood in the King List, was said to be two-thirds god and one-third human, and his reign was shortened to a few hundred years.
The Age of Mortals: With each successive generation, the "divine bloodline" became increasingly diluted. It's like a strong cup of coffee: the more water you add, the weaker the coffee flavor (i.e., the "divinity" and longevity genes) becomes. Eventually, the lifespans and reigns of kings gradually returned to the normal human levels we know today.

To summarize the theory's logic chain simply:

Prehistoric super-long reigns -> Because the kings were pure-blooded Anunnaki.
Why the Anunnaki lived so long -> Because their home planet Nibiru has a long orbital period, creating a different time scale from Earth.
Why reigns shortened -> Because after the Great Flood, Anunnaki intermarried with humans, leading to the dilution of the "divine bloodline" and a gradual decrease in lifespan.

A Note on the Mainstream Historical View

Of course, it's necessary to mention that mainstream archaeology and history do not accept this "Ancient Astronaut Theory." They argue:

Mythological Symbolism: These extraordinarily long numbers are a form of literary and mythological exaggeration, symbolizing the king's greatness, divinity, and the legitimacy of their rule. The longer the number, the more it signified the dynasty's divine favor and ancient origins.
Error in Calculation Units: Some scholars believe early Sumerians might have used different calendrical or counting units, such as recording a month or a season as a year, leading to misinterpretations during later copying and translation.
Divine Right of Kings: The purpose was to emphasize the concept of "divine kingship," tracing royal authority back to the mythical era to enhance the prestige of contemporary rulers.

So, as you can see, the Anunnaki theory provides a logically self-contained story explaining the "mystery of the lifespans" in the Sumerian King List. From the mainstream historical perspective, it's viewed more as a cultural and political symbol. Which one you believe depends on which story you find more interesting and convincing!