By the time the Egyptian twenty-fifth dynasty rolled around, the once-all-powerful domain of the Pharaohs really wasn't what it used to be. Sure, the New Kingdom was still a dominant civilization and a badass culture filled with awesome shit like mummies and pyramids and insane animal-head gods, but all-in-all things were a far cry from the "good old days" of Ramses II trampling cattle with his pimped-out war chariots or Thutmose III building giant obelisks out of human skulls, pipe cleaners, and crazy glue. Thanks to a mega-hot mix of apathy, ineffective leadership, and general political bitching/infighting, over the centuries this ancient and powerful civilization had fractured into several smaller kingdoms and provinces, with each one ruled over by some petty warlord or despot or some other such ridiculous nonsense.
As it is with most fractured regions desperately in need of conquest, a would-be tyrant soon arose. One day an ambitious dude named Tefnakht decided he was sick of that bullshit, and came up with the brilliant idea of reunifying Egypt under one ruler, installing himself as the all-powerful Pharaoh, and using his position as a living God-King to pretty much make life epically miserable for all sentient life on the planet. He put his master plan into effect by raising a ball-crushingly mighty army, scarfing down a couple pounds of crocodile jerky, plundering a bunch of cities along the Nile, and telling everyone he met that they basically had two real options – submit to his evil will, or die horrifically (prefereably screaming and/or in flames). Most people opted for the first of those two enticing alternatives, surrendering to the back-breaking Alpha Male warlord without a fight, and before long this Tefnakht fellow was well on his way to becoming Egypt's Next Great Warlord Killmaster.
Well running amok throughout Lower Egypt was great and all, but Tefnakht was a pretty standard-issue classical-age badass, and his kill-boner wasn't going to be successfully satiated until he'd more or less conquered damn near everything on the planet that was even remotely worth conquering. So of course after he forcibly reunified the Nile Delta region into a giant mish-mash of subservient automatons by bashing everyone's head in with an iron skillet, he decided it would be totally hilarious if he then marched his armies south and invaded the Nubian Kingdom of Kush for some reason.
What Tefnakht failed to recognize, however, is that Nubia - an ancient kingdom that existed in the northern part of the present-day Sudan - was a pretty badass place, and they didn't really respond well to the prospect of being conquered by some megalomaniac douchebag with too much spare time on his hands. These guys had been smashing heads with the Egyptians for centuries, and a few dozen generations of unstoppable assbeatings had established Nubia as a totally hardcore civilization that wasn't to be screwed around with. Tefnakht apparently didn't get that memo - he marched his massive force directly into the domain of a badass, face-crushing Nubian warlord known as Piye (or, alternatively, as Piankha, Py, Π, and god knows what else). This epic kicker of punk asses had ruled over Nubia for roughly twenty years at this point, and was known as a just, pious, and honorable ruler who stayed off drugs, said his prayers, ate his vitamins, and generally just tried to be totally awesome to everyone all the time - and this dude wasn't going to start coughing up blood just because some jerkwad Egyptian dillhole thought he was the hottest shit since unleavened bread.
When Piye first heard that Tefnakht was invading Nubia, he just laughed. Seriously, the prospect of some flacid, half-assed Egyptian invasion was just so uncontrollably hiliarious that this dude busted out a hearty guffaw so manly that it caused the Great Sphinx of Giza to spontaneously start growing chest hair. Once he got over the ridiculousness of this fucktard thinking he could conquer Piye's Kingdom, the Nubian King put together an army, made sacrifices in the name of the Sun God Amun, ordered his soldiers to sprinkle themselves with Holy Water, and then set North to show Tefnakht what it feels like to have your larynx pulled out through your rectum. Piye marched out, faced his army off against a coalition of three Kings and five Princes loyal to the Egyptian conqueror, and smashed them to shit. The enemy nobles and commanders lost their armies, fled the field, and ran off to their home castles, so just to drive home his point, Piye went around one by one besieging them until, in his words, they "exuded the stench of decomposition".
Once Piye got on a roll, all bets were off. He was in what we like to call "The Zone", and this guy just went nuts and started conquering everything he could find. His strategy was basically just to surround a city and demand that they submit to him. If they did, he would march in, plunder their treasury, and leave. If they crossed him (as was the case with the Egyptian metropolis of Memphis), he would destroy their army, sink their navy, and tear down the walls of their cities. He explicitly forbade his troops from any kind of plundering, pillaging, and raping, but don't let that fool you into thinking this guy was some benevolent pushover. Piye wasn't playing around - he just knew that he didn't need to set a bunch of peasants on fire in order to prove that he had giant stainless steel balls.
Tefnakht had woken a sleeping juggernaut of asskickery, and it wasn't long before Piye got the better of the situation, chased Tefnakht out of town (Tefnakht sued for peace soon after getting his nuts royally smashed by Piye, and is quoted as saying, "Be gracious! I cannot see your face in the days of shame; I cannot stand before your flame, I dread your grandeur."), conquered all of the cities Tefnakht had worked so hard to capture in the first place, and installed HIMSELF as Pharaoh. I love this because in the span of just a few years this dude had succeeded where his mortal enemy epically failed, and apparently did it without even really breaking a sweat. It seems that Tefnakht had fucked with the wrong man.
Interestingly, pretty much immediately after making himself Pharaoh, Piye bailed out and headed back home to Nubia. He spent the rest of his days living in his giant palace, never setting foot in Egypt again. He'd basically shown everyone that he was the toughest motherfucker around, and I guess he didn't really feel obligated to prove it to anybody.
What's also awesome about this is that when local leaders or officials wanted to have an audience with the Pharaoh, they had to ride all the way out to Nubia, and even embarking on a treacherous, week-long journey wasn't a guarantee that you were going to get to speak with the God-King. For instance, one time a group of four Egyptian princes rode out to speak with Piye, but he only let one of them come inside to eat dinner with him. It turns out that the other three dudes were fish-eaters, and Piye hated seafood, so he deemed that those fuckers simply weren't worthy of his time. They had to stand outside in the cold while Piye and the other prince chilled out and ate five giant heaping plates of sweet, delicious beef.
That's just how Piye did shit. He was a total megalo-egomaniac, which I find endearing. One of the best things about this guy is that when you read his account of the domination and conquest of Egypt, he basically describes his epic victories as unavoidable eventualities rather than towering deeds of awesome. He's just like, "Well, they pissed me off, so of course I utterly destroyed them and made myself Pharaoh. Then I went home and ate a pomegranate."
Piye conquered Egypt, ruled benevolently, chilled out in Nubia, carved out his story on a giant stone stele, and was buried in a totally sweet pyramid. Oh, and just in case you thought that bastard Tefnakht got off easy, I should mention that Piye's kid would go on to grab Tefnakht's kid and have him burned at the stake. So that's something.
Draper, Robert. "Black Pharaohs". National Geographic. February 2008.
Jenkins, Andrew and Jan Assman. Mind of Egypt. Harvard University Press, 2003.