The “Natural” Borders Of France

Map found on redditThe map above shows one interpretation of the “natural” borders of France. Here’s a bit more about the concept and where they should be:

The concept of “natural borders” (in French, les frontières naturelles) refers to the idea that France’s boundaries should align with significant geographic features that serve as clear and defensible frontiers.

This idea is rooted in both historical and nationalist rhetoric, particularly prominent during the French Revolution.

Advocates of natural borders have argued that France’s ideal borders should include:

1. The Pyrenees to the south (separating France from Spain).
2. The Alps to the southeast (separating France from Italy).
3. The Rhine River to the east (a disputed boundary with Germany and the Low Countries).
4. The Atlantic Ocean to the west.
5. The English Channel to the northwest.

These borders were not fully realized historically and have been the subject of various military and diplomatic efforts over centuries.

Timeline of Efforts to Achieve or Exceed France’s “Natural Borders”

Medieval Period

• Late 12th Century – 14th Century: The Capetian kings began consolidating French territories. The idea of “natural borders” was not yet formalized but set the stage for later territorial ambitions.
• Hundred Years’ War (1337–1453): Although territorial losses and gains shifted during this conflict, it ultimately ended with France consolidating most of its current territory.

16th Century

• Franco-Spanish Wars: France attempted to secure the Pyrenees as a southern border. The Treaty of Cateau-Cambrésis (1559) marked a temporary halt in these ambitions.

17th Century

• Reign of Louis XIII and Cardinal Richelieu (1610–1643): Richelieu sought to expand French influence eastward, strengthening the notion of France’s “natural borders.”
• Reign of Louis XIV (1643–1715):
  • Treaty of the Pyrenees (1659): Established the Pyrenees as the southern border.
  • Treaty of Nijmegen (1678): France annexed parts of the Netherlands.
  • Attempts to reach the Rhine: The Rhine remained a point of contention, with Louis XIV engaging in campaigns to secure this boundary.

18th Century

• War of the Spanish Succession (1701–1714): France’s ambitions were curbed by the Treaty of Utrecht, though it retained significant influence.
• Late 18th Century (French Revolution):
  • Revolutionary leaders advocated for the Rhine as France’s eastern border.
  • France annexed Belgium and parts of the Rhineland, claiming alignment with the “natural borders.”

19th Century

• Napoleonic Wars (1804–1815):
  • Napoleon extended French territory beyond the Rhine and into much of Europe, far exceeding the concept of natural borders.
  • Post-Napoleon, the Congress of Vienna (1815) significantly reduced French territorial gains.

20th Century

• World War I (1914–1918):
  • Alsace-Lorraine, lost to Germany in 1871, was reclaimed by France in the Treaty of Versailles (1919).
  • The Rhine served as a focus of French strategy, with French troops occupying the Rhineland temporarily.
• World War II (1939–1945):
  • German invasions challenged French territorial integrity, leading to post-war restructuring.
  • The establishment of the European Union later diminished the emphasis on territorial borders.

Modern Era

• France no longer actively pursues territorial expansion or “natural borders,” focusing instead on European integration and economic cooperation. The borders of France today align closely with its historical boundaries, solidified by treaties and international agreements.

What do you think Franc’s natural borders should be?