But starting around 5,000 BCE, we're going to see kind of farming villages pop up along the 750 strip of the Nile River. Now in the upper portion, which is that thin strip, you're surrounded by desert. So that's going to isolate those farming villages, allowing them to grow. We're not going to have a lot of invasions and warfare because of that natural protection. But it's also going to make trade a little bit more difficult because you're not going to be able to cross those deserts 5, 6, 7,000 years ago. Now the Nile, unlike the Tigris and the Euphrates and other rivers in early civilizations, is predictable. Some of those other rivers would just flood whenever the time would be.