Map Of The Competing Definitions Of The Boundary Between Europe & Asia

Map created by AotearoaEurasia is the largest contiguous landmass on Earth, but where the “European” and “Asian” parts begin and end is somewhat arbitrary. The map above looks at many of the competing definitions of the boundary between the two.

They are:

Red line – “Strahlenberg” border, allegedly also used by the International Geographical Union

• A: Ural Mountains-Emba River and Kuma Manych Depression (at Rivers Kuma, Manych and lower Don)

Orange lines – other variants of border:

• B: Ural Mountains-Ural River (modern mainstream definition)
• C: Yugorsky Strait Cape–Pay Khoy Mountains–Ural Mountains-Ural River
• D: Ural Mountains-Kazakhstan Border
• E: northern foothills of Caucasus
• F: Lines on the Great Caucasus watershed (modern mainstream definition)
• G: southern foothills of Caucasus
• H: Meso-Caucasus at Rivers Rioni and Kura
• I: Lines on the Lesser Caucasus and Rivers Araks and Kura
• J: former Soviet Union border

A little more about each:

Red Line: “Strahlenberg” Border (Allegedly used by the International Geographical Union)

• Description: Named after the Swedish geographer Philip Johan von Strahlenberg, this border runs along the Ural Mountains, Emba River, and the Kuma-Manych Depression, following the Rivers Kuma, Manych, and the lower Don.
• Significance: This border was one of the earliest modern delineations between Europe and Asia, and it played a major role in geographic definitions during the 18th century. It separates the Caspian and Black Sea basins and emphasizes the natural divides of rivers and lowlands.

Orange Line Borders – Other Variants:

A. Ural Mountains-Emba River and Kuma-Manych Depression (at Rivers Kuma, Manych, and lower Don)

• Description: Similar to the Strahlenberg border but slightly adjusted, it follows the traditional and historical routes that highlight significant geographical barriers such as mountain ranges and river valleys.

B. Ural Mountains-Ural River (Modern Mainstream Definition)

• Description: This is the most widely accepted definition today. It follows the Ural Mountains and then the Ural River to the Caspian Sea, clearly marking a natural border between Europe and Asia.
• Significance: It is the modern geopolitical standard, recognized internationally and taught in most geography texts.

C. Yugorsky Strait–Cape Pay Khoy Mountains–Ural Mountains-Ural River

• Description: This route includes the Yugorsky Strait and Pay Khoy Mountains, extending further north and emphasizing the geological structures that continue the Ural chain.
• Significance: It’s an extension of the Ural border concept into the Arctic regions.

D. Ural Mountains-Kazakhstan Border

• Description: This line follows the Ural Mountains and loosely aligns with Kazakhstan’s modern borders.
• Significance: It’s influenced more by political boundaries rather than strict geographical features.

E. Northern Foothills of the Caucasus

• Description: This border lies at the northern slopes of the Caucasus, below the mountains.
• Significance: It emphasizes the role of the Caucasus as a division between Europe and Asia, favoring lower, more accessible terrain.

F. Lines on the Great Caucasus Watershed (Modern Mainstream Definition)

• Description: This is the mainstream Caucasus border today, following the main watershed of the Great Caucasus range from the Black Sea to the Caspian Sea.
• Significance: This boundary is heavily influenced by the highest peaks and the main ridge, marking a clear and dramatic divide.

G. Southern Foothills of the Caucasus

• Description: This variant places the border along the southern slopes of the Caucasus, marking a southern separation point.
• Significance: It is less commonly used but represents a broader interpretation of the Caucasus as a frontier.

H. Meso-Caucasus at Rivers Rioni and Kura

• Description: This variant traces rivers Rioni and Kura through Georgia, splitting the Caucasus range at a median point.
• Significance: It is a less common boundary reflecting the central divides within the Caucasus region itself.

I. Lines on the Lesser Caucasus and Rivers Araks and Kura

• Description: A more southern line, passing through the Lesser Caucasus and the southern river valleys of Araks and Kura.
• Significance: This boundary extends the Europe-Asia divide further south, including parts of the Armenian Highlands.

J. Former Soviet Union Border

• Description: Based on the former USSR borders, this line uses political boundaries that were in place during the Soviet era.
• Significance: It reflects a geopolitical, rather than strictly geographical, boundary that was used for administrative purposes.