Tylos is a small city state located in the Persian Gulf in the region of Gedrosia, in what is now Bahrain. An important trading center for pearls and other exotic goods, Tylos was long colonized and controlled by the ancient Assyrians and Babylonians who continued to rule the island under the suzerainty of the Achaemenid and Argead empires and remains so as a tributary of the Seleukid Empire. Tylos is notable for being the only country at the start of the game that has Babylonian as its primary culture, which makes it a prime candidate for restoring Babylon if it can manage to break free from its Seleukid overlords and reconquer Mesopotamia for the Babylonians. Historically Tylos would continue to thrive as a center of trade and become increasingly Hellenized under the Seleukid Empire, eventually passing to 20px Parthia with their conquest of Persia and Mesopotamia.
As a Babylonian cultured country, Tylos has access to the decision to form Babylon.
Babylon the great, that most ancient of cities, which reigns over the kings of the earth; it is our destiny to break the yoke of our oppressors, and restore her to her people.
Tylos starts as a tributary to the Seleukid Empire. Unlike most subject types this diplomatic relation can be cancelled at any time without a war, though this may leave Tylos at the mercy of its much larger and stronger neighbour 20px Gerrha.
Tylos starts with a total of 27 pops in its single territory, mostly Makan Arabic (around 80%), but also with a substantial minority of Macedonian Hellenic pops that have recently settled in the region. Notably, Tylos does not begin with any pops of its primary culture (Babylonian), which makes managing pop happiness important in the early game until they can be assimilated.
As a reasonably populated city state, Tylos also has a very high proportion of citizens (60% at start), which means that it can easily achieve a very high research ratio and gain a large technology advantage over its larger neighbours.