In the 5th century BC Hippodamus of Miletus created the orthogonal urban plan and applied this scheme to Miletus and Piraeus. The Romans inherited the rectangular street plan from the Greeks and implemented it mostly in their military camps. This is how the military town Castrum Romanum was created.

However, the streets of Athens or Rome were not orthogonal. Both cities, representatives of the Greek and Roman cultures, do not posses these layout. The reason is that both of them already existed as significant cities with established planning structure by the time the new orthogonal way of urban planning started to implement.

The same can be said about Philippopolis. Built on the Trihalmie – a massif of three hills, the city obtained its orthogonal street grid when it descended to the plain during the Hellenistic era. The Romans used the inherited street structure; they developed and urbanised it.