Whoa, that required some work, but I managed to pull it off with some years to spare.
To the strategy:
Since Arabia flips Egypt, and I don't even start with the mess called India, there was only one direction to go from the start, Carthago. Luckily they had collapsed and I managed to take Carthago around 100AD. Meanwhile I concentrated on teching and I was among the tech leaders around 1000AD, I took Rome in 1400 and eventually I managed to get the conquerors in 1430 (BTW, Leoreth, Ethiopia doesn't get Askaris, only regular musketmen). I toyed with Aztecs and made peace with Incas. After getting Astronomy both vassalised to me.
Naturally after that I sent my settlers to NA and settled the NAn triad before the Americans spawned. Meanwhile in Europe solid France had crushed/conquered/capitulated Germany, Portugal, Ottomans, the Netherlands and Russia.

In 1900 Russia was devided between France and Ottomans, but France was still expanding in Middle East. I was building an army and teching. France was occasionally unstable, but never collapsed. Later France vassalised Mughals and Russia respawned, but got stomped by France yet again. Egypt vassalised to me. In 1938 a world war began between me and Spain + vassals and Incas conquered the spanish colonies in south America, after signing peace with them I declared war on England and conquered their holdings in NA.
There was a brief peaceful perido for the Ethiopian Republic, but in 1972 I and my vassals (Incas, Aztecs and Egypt) declared war on France and her vassals Germany, Mughals, America, Arabia and Portugal. Just look at that France in the 1972 map, it is unreal and stable! I had been airlifting Main Battle Tanks to Rome for decades and every one of them was needed when France poured down the Italian peninsula (check the power graph). I threw in some nukes to collapse them, but nothing worked. I nuked Wien twice before rushing in to get the free civic change (it had Christo Redentor), but France quickly reconquered it. My air supremecy eventually turned things in my favor and I conquered mainland France before 1990. But France was still alive, stable and kicking. Meanwhile I had taken Philadelphia and Boston in NA while burning Washington.
I took Berlin, Wien, Split, Constantinople and Angora from France before they finally collapsed in 1995, I had also taken Wilna from Germany. After France collapsed Germany and America capitulated to me immeatidely and I gifted Germany Berlin and Wilna to prevent them from collapsing. Turkey respawned and I let them keep Istambul. I had almost the land, but I was way behind in population, so it was time to gether nukes, meanwhile I teased, once again respawned, Russia by nuking them and bombing every one of their improvements in order to keep their pop down. I also took couple of their cities. In 2002 I brought apocalypse on earth by launching 10-15 tactical nukes (almost everybody had SDI) and few ICBMs. That was enough to give me 33% of world's population.
The empire:
I ended up destroying 171 mech infantries.