Does the omission of important Sumerian city-states such as Lagash from the King List undermine its credibility as a 'complete historical record'?

That's a fantastic question! Simply put: Yes, this omission does weaken its credibility as a "complete" historical record, but it doesn't completely destroy its historical value.

We can think of it using a more relatable example.

Imagine the King List as a "Corporate History"

Think about it: suppose there's a massive corporation, let's call it "Mesopotamia Group." Now, the current CEO of the group (say, a king from the city of Isin) wants to compile an official corporate history.

What's the purpose of this history book? It's to tell all employees and customers: "Our company is divinely ordained! From the very beginning, there has been a clear, singular line of leadership, from Founder A to B, to C, and finally to us. We are the legitimate successors!"

How would this "corporate history" be written? It would list successive CEOs and the headquarters city where they were based.

Early CEOs: Might be mythologized, saying each ruled for centuries and performed miracles. (This is like the prehistoric kings in the King List who ruled for thousands or tens of thousands of years).
Later CEOs: Would be listed sequentially, emphasizing the principle of "only one recognized CEO per term."

So, what role did the city-state of Lagash play?

Lagash was like a very powerful, exceptionally high-performing "branch manager" within the group. This branch developed remarkably well, becoming incredibly wealthy and militarily strong. At times, its influence even surpassed that of the "headquarters" at the time.

However, this "branch manager" never became the CEO of the entire group. He was just a powerful competitor.

So, when the current CEO compiles the official history, how would he handle this "Lagash branch"? He would likely choose to ignore it entirely. Why?

It undermines the "sole legitimacy" narrative: Including Lagash would mean admitting that "during the same period, besides our headquarters CEO, there was also a branch manager who was incredibly powerful." This would ruin the story of "divine mandate residing in a single line."
Political pettiness: Lagash was likely a competitor to the city-state (like Isin) compiling the King List. Praising your rival in the official history? That's unthinkable.

What Exactly is the King List?

Through this example, we can better understand the nature of the Sumerian King List:

It is not an objective history textbook: Its compilers were not aiming for an impartial, comprehensive record of everything that happened.
It is more like a piece of political propaganda: Its core purpose was to legitimize the power of the rulers at the time. It constructed a linear history of "divinely ordained kingship, passed down through generations" to prove that "the kingship is rightfully in our hands now."

Conclusion: How Should We View the King List?

So, back to your question: Does the King List's omission of important city-states like Lagash weaken its credibility as a complete historical record?

As a "complete" record, yes, its credibility is low. It is clearly not comprehensive; it's carefully curated and edited. The Sumerian world it depicts—where there was only one hegemon at any given time—doesn't match the real history revealed by archaeology, which shows numerous competing city-states coexisting.
But as a "historical document," its value is immense. Precisely because of its "incompleteness" and "bias," it allows us a glimpse into the political thinking of the ancient Sumerians.
- It tells us that the Sumerians believed "kingship" was a sacred, transferable force.
- Its omissions themselves are a clue, revealing who was in power when the list was compiled and who their rivals were—the ones they wanted to "ignore."

To summarize simply:

You cannot view the Sumerian King List like a modern World History textbook; if you do, you'll find it full of holes. You should see it as an ancient "campaign manifesto" or "official mouthpiece." To prove its own "divine right," it was willing to modify and simplify history.

Therefore, Lagash's absence is actually one of the best pieces of evidence helping us understand the true intent behind this document.