In the peace deal, take a province bordering either Rome itself or the Pope in general. You should also be able to sink their navy, as well as any other navy you encounter, as well. Your Neapolitan war may have started by now or not, but either way once you’re at war with them get your troops to Naples ASAP and siege down Naples while attacking the small Neapolitan army if they are roaming around. You could do other stuff if you want (I vassalized Athens) but choose wisely as you don’t want too much AE. In your peace deal with Byzantium, just take Istanbul. You don’t want them to get any allies whatsoever. Meanwhile, watch Naples closely and declare war on them the very second they gain independence from Aragon. In my game, Byzantium’s only ally was Serbia and I’ve seen that a lot so Byzantium should be easy. You can probably get an alliance with them once you’re at peace. When your claims are in, immediately attack Byzantium and start improving relations with Poland. You want claims on Byzantium, Circassia and Naples as Byzantium owns Istanbul, Circassia is a weak nation that can get you a foothold in the Russian region, and attacking Naples to take a province bordering the Papal State like Abruzzi is the best way to get in a position to take Rome. As for your opening moves, immediately start a spy network on Circassia, Byzantium and Aragon. You also want Poland to get a PU over Lithuania, but that’s what usually happens anyway. If they are, I recommend restarting as getting them as an ally will make taking Moscow, which is probably going to be the last of the three provinces you will take, much faster. When you start the game, check to see if Poland is not hostile or rivaled to you. This guide is primarily for people who are only really playing for the achievement this is just a way to get it as soon as possible. To get the Definitely the Sultan of Rum achievement via my strategy, you need to play as the Ottomans and own Istanbul, Rome and Moscow as cores. How to get the achievement Definitely the Sultan of Rum as fast as possible! Definitely the Sultan of Rum Achievement Guide

Eu4 aragonese spy network