A real time strategy game set in and around the Aegean Sea after the Crusader conquest of Constantinople in 1204. You play as one of the successive dynasties in the region, either as one of the Byzantine successor states, or on the other side as a vassal to the newly formed Latin Empire. The goal of the game depends on which side you play as, but the final goal is to control the city of Constantinople, either as a Latin vassal becoming Emperor or as a Byzantine successor reforming the Byzantine Empire. Other goals on the way "to the city" also depend on which side. As a Latin vassal, you must introduce and spread Catholicism in the region, as a Byzantine successor, you must protect and preserve Orthodoxy. This is done through building churches, sponsoring artwork and books, etc. To be able to do this you must collect resources that go into these projects, such as acquiring stone and marble for churches, or paper for books for example. To gain these resources you must either conquer territory that has these resources and create production centers, or trade for them with other dynasties. To protect these trade routes you need to assemble armies, which gives you another reason to arm your populace other than just conquest. In these turbulent times known as the Frankokratia, or rule of the Franks, you as the player can determine the fate of the Aegean and the people who live there, whether you bring them into the Catholic fold or bring about a resurgence of Orthodoxy and the Byzantine Empire, its all up to you and your actions.

There are three major factions in the game, and within them are multiple dynasties you can choose to play as. The factions are the Latin Empire, the Byzantine Successors, and the Outlying Empires. As the Latin Empire you are unable to play as the Latin Emperor in Constantinople, you have to play as one of their vassals, such as the Kingdom of Thessalonica or the Duchy of Athens, among others. As the Byzantine Successors you can choose to play the Empire of Nicaea, the Despotate of Epirus, or the Empire of Trebizond. As an outlying empire you can play as either the Seljuk Sultanate of Rum, where you can conquer Anatolia and spread Islam, or as the Bulgarian Empire where you can take advantage of the chaos to conquer the Balkans. The final goal is to take the city of Constantinople. If you do this as a Byzantine Successor state then you can reform the Byzantine Empire. As a Latin Vassal the goal is to overthrow your emperor and place you own dynasty on the throne. As the Seljuk Rum you want to avenge the defeat of the Arab Siege of Constantinople and finally conquer the city in the name of Islam. Constantinople is the greatest city on Earth and your goal is to control it to become the greatest empire on Earth.

After choosing your faction you are thrown into the map and must decide your course of action. You can choose where to place your buildings like you would in a city builder simulator. From some of these buildings you can recruit units, like priests and missionaries from churches and monasteries, or soldiers from barracks, all of which you can move around the map to fulfill whichever objective you want them to fulfill.  Goals in the game are mostly about spreading or preserving culture, which you must do through building certain buildings and units, which you can only acquire by collecting certain resources, meaning as the player you must expand your state to collect these resources and protect them. Thus logistics is an important aspect of the game. To expand your state requires a military, which are expensive to maintain meaning that you cannot just go on a conquering spree you must be strategic about when to raise your army and which regions you should attack. The final goal of the game is to take the city of Constantinople, while also spreading or maintaining your culture.