Reddit mentions of The Sumerians: Their History, Culture, and Character (Phoenix Books)

Since we've been waiting for nearly a day for answers in this thread (which is about some of my favorite topics to study), I'm going to list some factors I've read about. I know the mods are strict here, but I'll cite sources for every one of these factors, which I hope will count for something.

• Mesopotamia was much more geographically diverse. When we talk about "ancient Egypt," in terms of geography, we're really just talking about that narrow strip of arable land on the banks of the Nile. The vast majority of Egypt's population seem to have made their living by farming and fishing along that narrow strip, from prehistoric times all the way to the Roman period (and, to some extent, even into the present day). All along that strip of land, yearly floods and other seasonal factors exhibited similar patterns, making it relatively easy to plan harvests, centralize stockpiles and organize distributions of food and other resources all along the Nile. In fact, even nearby cultures - like the Kerma Culture and the Kingdom of Kush - which were genetically, linguistically and (to some extent) religiously distinct from Egypt, also made their livings from the Nile, which may be one reason why Egypt was able to conquer and control these kingdoms at various points in its history. Mesopotamia, on the other hand, was a forested plain bordered by swamps in the south, mountains to the north and east, and deserts to the west. From prehistoric times onward, this geographic diversity seems to have brought people with widely divergent cultures, beliefs and ways of life into conflict over the same pieces of land, where much of the agriculture was achieved by damming and building aqueducts from certain points on the Tigris and Euphrates. While one city reaped a bountiful harvest, a city just up the river might be starving - because when one city enjoyed a plentiful water supply, it was probably at the expense of a city downriver. In fact, the first recorded war in history was fought between the city-states of Lagash and Umma, over just such a water supply.
  
  
• Egypt was unified much earlier. While there's some evidence that Egyptian cities each worshiped their own gods during the prehistoric and proto-historic periods, many processes of linguistic and cultural unification seem to have taken place much earlier than in Mesopotamia - probably sometime between 6,000 and 3,000 BCE. In other words, Egypt most likely did go through an extensive period of immigration, city-state rules, warfare and unification - we just know very little about this process because most of it occurred before the invention of writing. All the large-scale cross-cultural migrations and wars were most likely wrapped up by the time of the pharaoh Menes (possibly the same person as Narmer) around 3,000 BCE. Mesopotamia, on the other hand, was still receiving massive immigrations of foreign peoples as late as the 500s BCE, and even later. This region was arguably truly unified for the first time under the Neo-Assyrian Empire throughout the 800s BCE, and was brought under more scrupulous (and less harsh) administrative control by the Achaemenid Persian Empire from the 500s to 300s BCE. So in that sense, Mesopotamia and Egypt didn't "start at similar times" - Egypt's processes of immigration and unification began much earlier, and were largely completed by the time Mesopotamian city-states really started waging war - and the new invention of writing was able to document those processes.
  
  
  
• Mesopotamia was more culturally and politically diverse. Because of these ongoing waves of immigration, there was a lot of trade, warfare, and cultural mingling going on from very early periods in Mesopotamia - and each group seems to have held onto certain cultural elements (languages, clothing and grooming styles) well into the historical period. Although groups like the Sumerians and Akkadians lived in the same cities and intermarried, they were each proud of their distinct languages and styles of dress. Meanwhile, other groups like the Elamites (based in what's now Iran, though not an Indo-Iranian people), the Kassites, the Hittites, the Assyrians, and many others, swept in from the geographical fringes at various times, sometimes ruling for a few hundred years; sometimes conquering, falling, and reconquering across thousands of years. Even the famous Babylonian king Hammurabi was the descendant of a foreign Amorite conqueror. While Egypt certainly fought with the peoples on its borders - most notably the Libyans (Libu), the Kushites, the Hittites and the Sea Peoples - and these peoples sometimes conquered and ruled Egypt (the 25th dynasty of Nubian Kushite pharaohs; the 23rd dynasty of Libyan Meshwesh pharaohs, and of course the Macedonian Greek Ptolemaic dynasty), Egyptian culture seems to have conquered these peoples as much as they conquered Egypt: the invaders seem to have adopted Egyptian fashions and religion, and followed the basic protocols of pharaonic rule. Many of them even seem to have adopted the Egyptian language - except for the Ptolemaic rulers, who (with the exception of Cleopatra) insisted on speaking only Greek at court.
  
  As with many distinctions in history, these aren't cut-and-dried. Egypt actually did exhibit quite a lot of cultural, political and religious variation throughout the Old, Middle and New Kingdoms; large swathes of Mesopotamia were unified under single rulers (Sargon of Akkad, Ur-Nammu and Hammurabi, for example) for a century or two, here and there; and remarkably diverse groups of people (Sumerians, Akkadians, Amorites and many others) seem to have lived in relative peace in many Mesopotamian cities.
  
  But the short answer to your question, based on sources I've read, is that the factors above are some of the most commonly cited reasons why Mesopotamia is perceived as more politically unstable than Egypt.
  
  Sources:
  
  
• Cultural Atlas of Mesopotamia and the Ancient Near East by Michael Roaf
  
• Ancient Mesopotamia: The Sumerians, Babylonians, and Assyrians by Virginia Schomp
  
• The Sumerians: Their History, Culture, and Character by Samuel Noah Kramer
  
• Babylon: Mesopotamia and the Birth of Civilization by Paul Kriwaczek
  
• The Archaeology of Mesopotamia: From the Old Stone Age to the Persian Conquest by Seton Lloyd
  
• Red Land, Black Land: Daily Life in Ancient Egypt by Barbara Mertz

Mesopotamian mythology (including the Sumerians, Akkadians, Assyrians, and Babylonians) is actually one of the better documented mythologies of the ancient world. Despite the preponderance of "ancient alien" nonsense out there, a plethora of scholarly books exist on the subject, as well as websites curated by academic groups.

• ORACC
  
  ORACC is an excellent place to start if you're interested in the major deities of Mesopotamia. Each entry contains historical information (cult centers, earliest attestation, etymology, etc), and well as mythology (genealogical, function in pantheon, etc). The entries are sourced, so you can follow up any queries you may have.
  
  
• ETCSL
  
  The ETCSL is a collection of Mesopotamian mythology in easy-to-digest format. Most of the material on here was written during the Old Babylonian period (c. 1800 BCE) but is based on earlier traditions found in the Akkadian and Ur-III periods (c. 2300-2000 BCE). A print-version of many of the myths contained on the webpage can be found on Amazon here.
  
  
• SEAL
  
  SEAL operates much the same as the ETCSL, only it is focused exclusively on literature from the Akkadian empire (c. 2350 BCE). If you follow the "corpus" link you'll be taken to the entire collection of texts SEAL has available for browsing.
  
  There are other such collections, similar to ETCSL and SEAL that are available online, but these are good starting points if you don't yet have your feet wet regarding the subject matter. You should also, if you're interested, explore print-material as well. Much of Mesopotamia's core research is published in book format, by professors and archaeologists who're still working on dig-sites or in universities.
  
  A few names and texts to consider:
  
  
• History Begins at Sumer
  
• The Sumerians: Their History, Culture, and Character
  
  Samuel Noah Kramer, who published the above, provides an excellent introduction to Sumerian culture and mythology. His books are easily readable and often times serve as most people's introductions to Mesopotamia.
  
  
• Religion in Ancient Mesopotamia
  
  Jean Bottéro's masterwork has been translated, but is approachable and easy to read. This volume explores the emotional and psychological connection of the Mesopotamian people to their religion.
  
  
• The Treasures of Darkness: A History of Mesopotamian Religion
  
• The Harps That Once: Sumerian Poetry in Translation
  
  Thorkild Jacobsen is one of the best translators of Mesopotamian material. These two books present dozens of myths, cult songs, and other works for the reader, while also exploring the patterns and motifs present in Mesopotamian religion across its 3000+ year history.
  
  There are other works I could recommend, but I don't want to overwhelm you with options. If you're interested, I also run the subreddit /r/Sumer, which is dedicated to reconstructing the religious beliefs and practices of the Mesopotamian people. It isn't the most active of places, but I'm still trying to get it off the ground. Feel free to join us over there if you wish.

Sorry for your disappoint. However, you STILL might find some historical writing pretty fascinating. Try reading Inanna, Goddess of Heaven and Earth or Sumerians, might just be what you're looking for.

Get The Sumerians
Here is a free summary
This is actual documented history, proof that the Bible, Torah & Quran are just derivatives of an even more ancient rich culture who had a polytheistic mythology.