So I realised my knowledge of ancient Egypt history is essentially:
"So you have a few kingdoms pop up up and down the Nile, they go to war a few times unite and split up until they're eventually unified (also a bunch of semi mythical pharaohs), Egypt goes to war with the Hittites over the levant and then have a peace treaty, then they get raided by sea people and the whole infrastructure of bronze age Egypt sorta colapses but not to the extent of the rest of the Mediterranean; fast forward a few centuries and Persia conquers Egypt, then Alexander conquers Persia, then Alexander dies and Ptolemy dibs Egypt, a bunch of shenanigans later and boom Egypt is a Roman province."
I feel like historians and archaeologists are more interested in figuring out what was happening in Greece during the Mediterranean dark age rather than Egypt which was still doing pretty well.
Well, let's start with the Sea Peoples then. Screw it, this is just gonna be a very long answer.
Sometime around 1177 BCE Rameses III famously repelled an invasion by some kind of a coalition of peoples from the Mediterranean. Around the same time, he also had to deal with two invasions from Libya (c. 1180 and 1174). The expense of these campaigns struck right at the same time that the eastern Mediterranean was sent spinning into economic collapse, and that's what really drove the Bronze Age collapse home in Egypt. Mycenaean Greece and the Hittite Empire fell completely, leaving Egypt without major nearby economic partners and Urartu was destroyed while Karchemish became the site of competing Hittite royals, largely cutting off trade with Mesopotamia as well (not that the Mesopotamians weren't dealing with their own problems too).
Rameses III had to deal with internal unrest as the result of these economic troubles and a general period of global cooling and poor agricultural conditions all at the same time. Nobody was happy with him. Common people were refusing to work and nobles plotted two assassination attempts. He survived the first one but in c. 1155 BCE Rameses III's throat was slit. Egypt burned through eight kings, Rameses IV-XI, in the next 78 years. Economic troubles, palace coups, drought, famine, and the resulting civil unrest all took their toll, and by 1077 there were no heirs of the 20th Dynasty left.
This is traditionally seen as the start of the Third Intermediate Period in Egyptian history, though if you're looking at trends rather than dynasties, you could argue that it started in 1156. The royal titles passed to one of Rameses XI's son-in-laws marking the start of the 21st Dynasty. Over the course of the later 20th Dynasty, the Pharaohs had essentially lost control of southern Egypt. The High Priests of Amun, usually still cousins of the royal family, essentially governed as they pleased from Thebes. None of these High Priests or the nobles in the south ever tried to declare themselves Pharaoh outright, but if the actual Pharaoh tried to give them orders, they just ignored it.
The situation started to stabilize around 1000 BCE. The Egyptian economy had recovered and the global cooling period that characterized the Bronze Age Collapse had ended, allowing Egypt to recover some of its agriculture. The 21st Dynasty capital at Tanis was now the site of monumental building projects, and the High Priest of Amun even acknowledged the supremacy of Pharaoh Amenemope. Ironically, Amenemope achieved the de facto reunification of Egypt in part by claiming the title "High Priest of Amun at Tanis. After more than a century of priestly rule, that was almost as important a title as Pharaoh.
This was also the period where Egypt started projecting power again. By the end of the 20th Dynasty, the Pharaohs struggled to field armies in Nubia and Sinai. By the early 10th Century, Amenemope and his successors started sending armies into Palestine to exact tribute for the first time in more than a century. This military build up was ultimately the downfall of their dynasty. Sometime around 943 , the commander of the Egyptian army declared himself Pharaoh Shoshenq I, starting the 22nd Dynasty.
Economically, Shoshenq's takeover did not change much. Egypt was still slowly recovering in the absence of other major political powers in the region. Politically, Shoshenq's successors seem to have fought among themselves frequently. The order of the succession is unclear and multiple Pharaohs claiming some kind of relation to Shoshenq seem to have claimed the royal titles simultaneously. By the time of Shoshenq's grandson, Takelot I, two of Shoshenq's other grandsons were the High Priests of Amun in Thebes, once again refusing to acknowledge their brother's royal authority around 880.
Unlike the last time that happened, the High Priests just acknowledged their own power outright and claimed the royal titles, making them the 23rd Dynasty. This left Egypt with two ruling dynasties descended from Shoshenq I. In the south, the 23rd Dynasty was plunged into an open civil war following a succession dispute that lasted from c. 835-800 with a two competing lines of succession.
Meanwhile, the 22nd Dynasty passed to Osorkon II in the north, who couldn't spare resources to do anything about his cousins in the south because the Assyrian Empire had suddenly appeared to the northeast and was threatening Egyptian vassals in Palestine and Phoenicia (by now including the Biblical kingdoms of Israel and Judah). He and his successors did not fight the Assyrians directly, but supported proxies in Canaan and Syria. Ultimately, this strategy was not successful and the Assyrians reached as far south as the Dead Sea anyway.
The Civil War in Thebes did end around 800, and the reigns of the rest of the 23rd Dynaty Pharaohs are not well attested. However, southern Egypt was clearly weakened by this infighting, which had also given the Nubian Kingdom of Kush time to build up its strength in modern Sudan. Under King Piye, the Kushites invaded Egypt and conquered Thebes in 744. Piye took the titles of Pharaoh and consolidated his power in the south, creating what Egyptologists acknowledge as the 25th Dynasty.
In the north, the 22nd Dynasty just kinda ends. Pharaoh Osorkon IV drops from the historical record in 716 and there are no known successors. A two successive rulers in the Western Nile Delta unified some semi-independent cities in that region to resist Nubian aggression, and are known as the 24th Dynasty. Piye died with only the southern and eastern Nile Delta under his control, but his successors completed the conquest of Egypt and stomped out the 24th Dynasty in 712.
Even though Egypt was conquered territory, the Kushite Pharaohs embraced Egypt and its culture. Nubia and Egypt had been engaged in cultural interchange for millennia, but the 25th Dynasty pharaohs used the wealth of their whole empire to engage in a period of cultural Renaissance in Egypt. Traditional Egyptian temples and artwork saw more patronage than they had in centuries. They even relocated their imperial capital to the traditional seat of Egyptian power in Memphis. The 25th Dynasty Pharaohs were also more secure and willing to engage in direct intervention against the Assyrians to protect their few remaining vassals in the north, specifically intervening and losing in an uprising from the Philistine city of Ashdod.
Conflict with Assyria was ultimately the downfall of their dynasty as well. Conflict with Assyria escalated under Pharaoh/King Taharqa, who was crowned in 690 . He campaigned in nominally Assyrian territory and pulled some cities in Palestine and Phoenicia out of Assyrian hands, while supporting unconquered territories like Judah when they resisted Assyrian attacks. Naturally, this drew Assyrian responses.