In late antique, the territory of the Eastern Adriatic coast is of extreme importance. Due to suitable navigable area of the Adriatic sea, various occurrences were conducted, such as trade or even warfare. Thus, the highly important role of the Adriatic territory in ancient world led to turbulence between major centers over its occupancy. During the imperator Justinian, the area possession system comes to its peak, which can be seen in the remains of the fortification architecture. The fortifications on the eastern Adriatic coast are located in dominant positions, and they spread from Istrian peninsula until Elafites. Many fortifications in its internal space contains sacral arhitecture (Krk – Korintija, Rab – sv. Kuzma i Damjan, Pag – sv. Juraj, Tribanj – Šibuljine – sv. Trojica, Mokro polje - Čuker, Pašman – Ćokovac, Osinj – Gradina, Sušac – Uvala Portić), and there are fortifications which in its vicinity have sacral arhitecture with which were probably related (Veliki Brijun – Kastrum, Krk – Glavina, Kornat – Toreta, Vrgada – Gradina, Mljet – Polače). The amount of religious architecture indicates the importance of religion to the inhabitants of the fortifications on the Eastern Adriatic coast in the late antique. Byzantine limes is an important defense architecture system and as such it should be studied as coherent whole, of course also looking at the other aspects and combining other scientific disciplines.