Subsequent boundaries are political borders that develop after human settlement in a particular area. Unlike antecedent boundaries, which exist before significant human occupation, subsequent boundaries emerge in response to cultural, social, economic, and political changes. These borders often adapt to existing patterns of human geography, making them highly relevant in the study of political geography.
Over time, these boundaries can shift due to wars, treaties, decolonization, or changing cultural and ethnic landscapes. Many of the world’s most politically sensitive borders are subsequent boundaries, as they reflect complex historical interactions among different groups. While some have been accepted and stabilized over time, others remain sources of conflict, negotiation, or geopolitical tension.
Characteristics of Subsequent Boundaries
Subsequent boundaries share several defining characteristics that distinguish them from other types of borders:
Established After Human Settlement – These boundaries are drawn after people have already occupied and developed the land. Their placement is influenced by social and political developments rather than natural features or arbitrary lines.
Reflect Cultural, Ethnic, or Economic Differences – Unlike geometric or superimposed boundaries, subsequent boundaries often align with linguistic, religious, or ethnic divisions that have developed over time.
Subject to Change Over Time – Because they are formed based on human factors, subsequent boundaries are not permanent and may shift due to changing political circumstances, war, or negotiations.
Can Be Either Peaceful or Contested – Some subsequent boundaries form naturally and are widely accepted, while others lead to long-term disputes, separatist movements, or even armed conflicts.
Tend to Have Historical Significance – Many of these boundaries were shaped by historical events, independence movements, and the rise and fall of empires.
Types of Subsequent Boundaries
Ethnographic Subsequent Boundaries
These boundaries emerge based on existing cultural or social divisions. They form naturally over time and align with ethnic, linguistic, or religious differences within a region.
Political Subsequent Boundaries
These boundaries are often the result of political treaties, negotiations, or changes in governance. They do not always follow cultural or ethnic divisions and can sometimes lead to disputes when they fail to align with the identities of the populations they divide.
Example 1: The Boundary Between Northern Ireland and the Republic of Ireland
One of the most significant examples of a subsequent boundary shaped by religious and cultural divisions is the border between Northern Ireland (part of the United Kingdom) and the Republic of Ireland.
Historical Background
For centuries, Ireland was under British rule, with many Irish people pushing for independence due to cultural and religious differences.
In 1921, the Anglo-Irish Treaty led to the partition of Ireland, creating the boundary between Northern Ireland and the Republic of Ireland.
This border was largely drawn based on religious demographics:
Northern Ireland remained part of the United Kingdom, with a majority Protestant population.
The Republic of Ireland became an independent, Catholic-majority state.
Many Irish nationalists in Northern Ireland opposed the partition and wanted to unite with the Republic of Ireland, while others supported remaining in the UK.
Social and Political Impact
The Troubles (1960s–1998) – This period of conflict involved violence between:
Unionists (mostly Protestants) who wanted Northern Ireland to remain in the UK.
Nationalists (mostly Catholics) who wanted Northern Ireland to become part of the Republic of Ireland.
The conflict led to bombings, assassinations, and military intervention, causing thousands of deaths.
In 1998, the Good Friday Agreement was signed, allowing:
Open borders between Northern Ireland and the Republic of Ireland, reducing tensions.
A power-sharing government in Northern Ireland, giving both communities representation.
Brexit (2016) reintroduced border concerns:
Northern Ireland remained part of the UK, while the Republic of Ireland stayed in the EU.
This created debates over customs and border controls, as the EU and UK have different trade policies.
Example 2: The Balkan States – Changing Boundaries Due to Ethnic and Religious Conflicts
The Balkan Peninsula is a prime example of subsequent boundaries evolving due to ethnic and political conflicts.
Formation of the Balkan Boundaries
For centuries, the Ottoman Empire controlled much of the Balkans, creating a region with diverse ethnic and religious groups.
As the empire weakened, different nationalist movements emerged, leading to wars of independence in the 19th and 20th centuries.
In 1918, the region was unified as Yugoslavia, bringing together Serbs, Croats, Bosniaks, Slovenes, Montenegrins, and Macedonians.
However, in the 1990s, Yugoslavia collapsed, leading to the formation of several independent states:
Slovenia, Croatia, Bosnia and Herzegovina, North Macedonia, Montenegro, and Serbia.
Ethnic and Religious Factors
The Balkans have historically been divided among three major religious groups:
Eastern Orthodox Christians (Serbs, Macedonians, Montenegrins).
Catholics (Croats, Slovenes).
Muslims (Bosniaks, Albanians, some Serbs and Croats).
These divisions led to violent conflicts, including:
The Bosnian War (1992–1995) – A brutal conflict involving ethnic cleansing between Serbs, Croats, and Bosniaks.
The Kosovo War (1998–1999) – A war between Serbian forces and ethnic Albanians, leading to Kosovo’s independence in 2008.
Political and Social Impact
The Dayton Agreement (1995) ended the Bosnian War, but Bosnia and Herzegovina remains a highly divided state with complex governance.
Kosovo’s independence remains disputed, with some nations recognizing it and others, including Serbia, refusing to do so.
The breakup of Yugoslavia shows how subsequent boundaries continue to shape global geopolitics.
Other Notable Examples of Subsequent Boundaries
The India-Bangladesh Boundary
Partition of India (1947) led to the creation of Pakistan, which later split into Pakistan and Bangladesh in 1971.
The boundary is shaped by religious and linguistic divisions.
The region had over 200 enclaves, which were only resolved through agreements in 2015.
The Sudan-South Sudan Boundary
South Sudan gained independence in 2011 after decades of civil war.
The border separates Muslim-majority Sudan from Christian-majority South Sudan.
Disputes continue over oil-rich territories like Abyei.
How Subsequent Boundaries Impact Political Geography
Cause of Conflicts and Wars – Many subsequent boundaries lead to ethnic conflicts and geopolitical disputes.
Economic and Trade Consequences – Some borders disrupt economic cooperation, while others foster trade.
Influence on National Identity – Boundaries shape how people identify culturally, politically, and religiously.
Modification Through Treaties and Agreements – Subsequent boundaries often change due to diplomatic negotiations and peace treaties.
FAQ
Subsequent boundaries form in response to cultural, ethnic, religious, or political divisions, which can lead to deep-rooted tensions. Unlike geometric or antecedent boundaries, subsequent boundaries often divide groups with long-standing rivalries or conflicting national identities. This can cause disputes over territory, governance, and resource control. For example, the partition of India in 1947 created a boundary between India and Pakistan, resulting in violent clashes and ongoing conflicts over Kashmir. Similarly, in Sudan and South Sudan, the boundary continues to fuel disputes over oil-rich regions and ethnic divisions.
Subsequent boundaries are also more prone to political manipulation, with governments redrawing them to consolidate power or marginalize certain groups. In some cases, these boundaries remain contested for decades, leading to civil wars, separatist movements, and forced migrations. Unlike relic or antecedent boundaries, which tend to be more static, subsequent boundaries are subject to change, often reflecting power struggles between different groups or states.
Economic factors play a crucial role in both the formation and consequences of subsequent boundaries. Many of these boundaries emerge due to competition for resources, trade opportunities, and economic disparities. When a boundary divides groups with unequal access to economic resources, tensions often arise. For instance, the Sudan-South Sudan boundary is highly contested because of its rich oil reserves, which both nations rely on for economic survival. This division has resulted in economic instability, as South Sudan lacks pipeline infrastructure to export oil without relying on Sudan.
Additionally, subsequent boundaries can restrict trade and migration, further exacerbating economic disparities. The partition of India and Pakistan not only created religious divisions but also disrupted historical trade routes, harming economic cooperation. Similarly, the Brexit-related debates over the Northern Ireland border highlight how economic concerns, such as customs regulations and market access, influence the enforcement and significance of political boundaries. In many cases, economic inequality along a subsequent boundary can prolong conflicts and hinder development, making it a key factor in geopolitical struggles.
Governments frequently manipulate subsequent boundaries to consolidate control, promote nationalism, or suppress opposition groups. One way they do this is through gerrymandering, where political boundaries are redrawn to benefit a particular party or ethnic group. This has been seen in post-independence African nations, where ruling elites have adjusted boundaries to maintain power.
Another strategy is border militarization, as seen in Northern Ireland during The Troubles, where British forces controlled crossings to prevent unrest. Similarly, the Berlin Wall (before its fall) reinforced a political divide between East and West Germany, even though the underlying national identity of Germans was shared.
Governments may also use boundaries to legitimize new states. In the Balkan region, new national boundaries after the breakup of Yugoslavia reinforced ethnic identities, even when populations were mixed. By controlling boundaries, governments can assert sovereignty, limit migration, regulate trade, and influence diplomatic relations, shaping national identity in the process.
Although subsequent boundaries are primarily based on human geography, environmental and geographic factors often influence their formation. Natural barriers like mountains, rivers, and deserts frequently shape these boundaries because they act as physical obstacles to movement and communication. For instance, the boundary between India and Pakistan is partially defined by the Thar Desert, which acts as a natural divider. Similarly, in the Balkans, the mountainous terrain contributed to the fragmentation of different ethnic groups, reinforcing the emergence of new national boundaries.
Geographic factors also impact how well subsequent boundaries are enforced. Borders in dense jungles, deserts, or remote mountains are harder to control, leading to disputed territories and smuggling routes. This can be seen in Sudan and South Sudan, where parts of the border are located in rugged terrain, making monitoring difficult. Climate change can further impact these boundaries, as shifting landscapes (e.g., rising sea levels) may force countries to renegotiate their borders.
In some cases, rivers that serve as natural boundaries shift over time, leading to border disputes. This has happened with the Shatt al-Arab waterway, which forms part of the boundary between Iran and Iraq. Overall, while subsequent boundaries are politically driven, physical geography often influences their placement, stability, and enforceability.
Subsequent boundaries often alter migration patterns by restricting movement, displacing populations, or creating new migration corridors. When a new boundary divides ethnically or culturally similar communities, people may relocate to align with their identity. This happened in India and Pakistan after the 1947 partition, when millions of Hindus and Muslims migrated across the newly established borders, leading to one of the largest mass migrations in history.
In some cases, subsequent boundaries create refugee crises, as seen in the Balkans during the Yugoslav Wars, where ethnic violence forced large-scale displacement. Similarly, the boundary between Sudan and South Sudan has led to ongoing migration due to conflicts and economic instability.
Even when migration is not forced, subsequent boundaries can shape economic migration trends. The Northern Ireland-Republic of Ireland boundary remained highly militarized for decades, limiting economic mobility, but after the Good Friday Agreement, migration between the two regions increased significantly.
Governments may also implement strict border controls to prevent migration across subsequent boundaries. For example, the border between North and South Korea, though not a classic subsequent boundary, is an example of how political tensions can completely halt movement across a divided region.
Ultimately, subsequent boundaries often dictate who can live where, influence labor markets, and shape regional identities, making them a crucial factor in migration studies within human geography.
Practice Questions
Explain how subsequent boundaries differ from antecedent boundaries, using specific examples to support your answer.
Subsequent boundaries develop after human settlement, reflecting cultural, ethnic, or political divisions, while antecedent boundaries exist before significant settlement. The boundary between Northern Ireland and the Republic of Ireland is a subsequent boundary, shaped by religious and political differences following British rule. In contrast, the U.S.-Canada border along the 49th parallel is an antecedent boundary, drawn before major settlement. Unlike antecedent boundaries, subsequent boundaries can change over time due to political or social conflicts, as seen in the shifting borders of the Balkan states after the breakup of Yugoslavia.
Describe how subsequent boundaries can contribute to political conflicts. Use examples to illustrate your response.
Subsequent boundaries often divide groups based on ethnic, religious, or political differences, leading to tensions. The border between Sudan and South Sudan, drawn after South Sudan’s 2011 independence, remains disputed due to oil resources and ethnic divisions. Similarly, in the Balkan region, the breakup of Yugoslavia created new states but also ethnic conflicts, particularly in Bosnia and Kosovo. The Northern Ireland conflict ("The Troubles") arose from political divisions reinforced by the boundary with the Republic of Ireland. These cases show how subsequent boundaries can become sources of separatist movements, violence, and geopolitical instability.
