Saharan, Nubian, Arabian.
The Sahara Desert was the southern border of the roman empire
The Narbada River
Sahara
The Danube River formed the northern boundary of the Byzantine Empire for much of its existence. It served as a natural barrier against invasions from various tribes and peoples in Central and Eastern Europe. The river was crucial for trade and military movements, facilitating connections between the empire and its northern territories.
The Danube River and the Carpathian Mountains formed the northern boundary of the Roman Empire. This natural barrier served to protect Roman territories from invasions by various tribes and groups from the north. It delineated the frontier between the empire and the lands inhabited by Germanic and other tribes, playing a crucial role in the defense and administration of Roman provinces in the region.
Hadrian's Wall in Britain the Danube River in Continental Europe
The Sahara Desert was the southern border of the roman empire
The Narbada River
Sahara
The western boundary of the Roman Empire was the Atlantic Sea. The eastern boundary was Persia (modern day Iran and central and southern Iraq).
The physical feature that formed the northeast boundary of Asoka's empire was the Himalayan mountain range.
The Syrian Desert.
The Yellow Sea formed the eastern boundary of Shang territory, while the Yangtze River marked the southern boundary.
The most Eastern Boundary of Rome was Constantinople which would later become the Capital of the eastern roman empire and then the Byzantiniam empire
In 1802, the Mississippi River formed the western boundary of the United States. The southern boundary extended to the 31st parallel north latitude.
Most of the northern boundary is formed by the Alps. However, on the Iberian Peninsula, the Pyrenees form another northern border of Southern Europe.
Constructive