We've reached our final destination

Phew! Over the past few months we’ve managed to go through a fair bit! During this time we’ve looked at a variety of case studies of civilization collapse from around the world. On our journey we’ve been to Mesopotamia to meet the Akkadians, to Mesoamerica for our Mayan friends, on to Easter Island to chill with our Rapa Nui buddies and have stopped off in Cambodia to see the Khmer gang.

During our travels we’ve looked at an assortment of factors that have led to civilization collapse. 

These have included:

•          Social: tension, unrest and rebellion, disease
•          Political: conflict, invasion, power relations
•          Economical: costs and losses, trade
•          Religious: the shift in religious authority
•          Environmental: drought, deforestation, resource exploitation, rats!

These key factors combine all our case studies together as they often share more than one similarity. I think from all case studies we’ve looked at, it’s clear that collapse is never simple. It is important to consider how all the elements interact. As new evidence emerges older theories either gain more validity or are shunned. However, when looking at all the examples covered, I think that environmental change is the greatest threat to civilizations and in the past has played a pivotal role in collapse. The response to such events can be the nail in the coffin.

To relate back to an article from a previous post, an article by Wiener (2014) published last year shows the importance of connectedness of a society for its survival. This Network Theory demonstrates how the more interconnected the civilization, the easier it’ll be to resolve issues. If a society is isolated (such as the Rapa Nui on Easter Island) this can be difficult and the critical stress threshold can be reached quickly, after which the entire system will collapse.

Most societies today are highly interconnected, which may act as a buffer against the climate changes that are approaching and help maintain functioning societies. However we must not rely on this. Lessons can and must be drawn from the examples of civilization collapse we’ve seen. Today, societies around the world face the threat from climate change on top of deep running social, political and religious tensions. If we do not learn from the mistakes of past societies, many may be heading for a similar fate. We need to develop an understanding of underlying environmental changes that may lead to social unrest, economic losses and political instability and we must mitigate them!

Sadly, for now, this point marks the end of our travels, I hope you've enjoyed reading about the different forces behind collapse. 

Until next time!

Source: Auditel

Tying up the loose ends

So we've looked at some different theories behind the collapse of the Khmer empire, including:

• Climate events such as drought and changes in the monsoonal system
• War and conflict
• Socio-political unease

Diamond, 2009 is a nice article that ties together all the interweaving aspects involved in the Khmer empire's demise. It also neatly (maybe too neatly) links the collapses of the Khmer empire, Mayas and Inca together.

Diamond demonstrates how a boom in agriculture in Angkor led to population growth that placed pressure on the Angkor infrastructure. Deforestation, resource exploitation and land degradation followed in attempt to sustain its large population. Socio-political unease, conflict with neighbouring cities and over reliance on a vulnerable irrigation system ultimately led to the collapse of the Khmer empire. Although this article is a few years old, it covers important factors of collapse that still exist in contemporary understanding (shown in more recent articles I've looked at). However I think it over-simplifies civilization collapse and presents a homogenous theory that is not fully representative of the variance between case studies. 

Take a look at this clip from a National Geographic documentary on Angkor Wat. See the whole video on Youtube

Also have a quick read of the New York Times article by Maugh (2010). It's a good summary piece and I'm glad to see that they have acknowledged the role of factors other than climate.

Looking at the literature, I think that climate probably had a lot to do with collapse. Changes in the monsoon system would have come as an unpleasant surprise to the people of the Khmer empire. This climate change had serious impacts on agriculture and water resources that the empire could not overcome. However a society's response to environmental change is also important. In the case of the Khmer empire and its centre Angkor, fear and confusion over the change in climate acted to undermine the authorities. Matters were probably made worse by conflict with other empires and within the empire.

Keep your eyes peeled for my next post, when I'll summarise what we've found about civilization collapse in general.

Trade and social unease

Lieberman, 2011 argues that changes in trade and socio-political unease were central to the collapse of the Khmer empire. These factors also contributed to the collapse of centres of other civilizations in Asia.

A shift from terrestrial to maritime trade undermined the centre of the Khmer Empire, Angkor, and enabled once peripheral cities of the empire to become new centres of power, based on proximity to maritime trade. Key shipping routes bypassed Angkor and led to economic instability and eventual collapse. These arguments have more recently been developed by Evans et al, 2013.

As a result of shifts in trade and subsequent political disorder and fragmentation, Angkor placed greater pressure on its people. Angkor exhausted its people by focussing a lot of energy on constructing grand architectural structures, most significantly Angkor Wat. With growing social unease and simultaneous expansion of Buddhism, many civilians converted to Buddhism, which worked to undermine the ideological system that had once allowed the growth of Angkor.

Evans et al takes it further and argues that the centre of power was shifted from Angkor to coastal areas that would benefit from the new maritime trade. This, on top of social unease and dramatic religious change, led to mass outward migration and Angkor's collapse.

Source: Cartoon stock

In Lieberman’s opinion, this social unrest was made worse by ecological deterioration and declining agricultural output as a result of drought. Labour and land productivity fell which made the heart of the Khmer empire particularly vulnerable to the military attack that occurred in 1432. Following this attack universal conscription across the city was implemented. This drew attention away from other pursuits, such as stabilizing trade and agricultural output.

Evans et al argues that the urban intensification that had occurred during the zenith of the Khmer empire made the situation worse.

Till next time!

Huh! War! What is it good for? Absolutely nothing!

The idea of conflict as the cause of the Khmer Empire's collapse originated in 1951 in Brigg's 'The Ancient Khmer Empire', but it has always been debated. Very few contemporary articles promote this theory. Having said that, Chachavalpongpun, 2012 plainly states that the Khmer Empire fell into decline after it was invaded by an army in 1431. He proposes that this was the cause behind the demise of Angkor and marked the point in time when the Khmer Empire fell and its structures were absorbed by the new emperor, Siam. He argues that this form of struggle has persisted throughout the history of conflict between Thailand and Cambodia. An article for the Ancient History Encyclopaedia by Plubins, 2013 (mentioned in a previous post) also asserts that the invasion of the Thai army was the key factor that led to collapse. 

Several blogs, such as Angkor History, The Angkor Empire, Environment and Conflict and The Warfare Historian, argue that conflict played an important role throughout the Khmer Empire's history and in its demise.

A wall carving from Angkor Wat, depicting the Khmer army marching into battle against the Chams from Vietnam. Source: Photo bucket

It may be that this theory deserves more attention from contemporary academics. As mentioned in my first post on the Khmer empire, few historical records exist after 1300s which may make this difficult. On the other hand it could be that there is little evidence to support it.

It would not come as a surprise to me that following a period of instability, the heart of the Khmer empire, Angkor, was attacked. Alternatively in combination with other factors such as environmental change and a lack of food and water, conflict within the empire may have occurred. I do not doubt that this civilization experienced a long history of conflict, however I do not believe it was the main cause of their demise. In my next few posts I’ll have a look at some other possible triggers, such as changes in trade.

Stay tuned!

The Hydraulic City

Buckley et al, 2010 present a good argument for the role of climate in the demise of the Khmer empire. Using Vietnamese tree rings that span the past 750 years, they show how severe inter-annual and inter-decadal drought periods intersected by intense monsoonal rainfall acted as a stressor leading to this societies’ collapse.

Angkor, the capital of the Khmer empire, if often referred to as the ‘hydraulic city’. This is because of the extensive canal, embankment and reservoir networks that supplied the city and its sprawling suburbs with water and irrigation for agriculture. These networks once supported a complex agricultural system.

A diagram of the water network in Angkor. Source: Blogspot

As the city expanded however, these networks became increasingly complex, convoluted and more difficult to manage, making them more vulnerable to large scale climatic events. Buckley et al argue that the tree rings show a severe drought at the time associated with the collapse of Angkor, which coincides with the transition from Medieval Climate Anomaly to the Little Ice Age. Drought periods were then disrupted by period of intense rainfall. This combination of drought and intense rainfall exacerbated erosion in the northern catchment. This sediment was then washed into the water system in the south which resulted in blocked water networks and the in-filling of canals. Buckley et al suggest that a single severe flood event could fill an entire canal section. In Angkor today, evidence of modifications in attempt to solve incurable failures in the water network can be found. 

Many academics have developed these arguments more recently and the argument remains very much the same. There is a vast amount of evidence from paleo-climate proxies that supports this theory and this argument has become a key explanation for the collapse of the Khmer empire. Although only the abstract is available at the moment, Afrifa et al, 2014 demonstrate the ongoing development of this theory. Fang et al, 2013 explain how drought, caused by a reduced Asian summer monsoon and dampened Westerlies, was a key factor in decline.

Angkor Wat, surrounded by a major water work. Source: Angkor Guide

In one case, radiocarbon dates taken from sediment found in a canal showed that it was filled in during the 14^th century. This shows that the canal was filled by flood debris from the time of Angkor and was never cleared out. This specific canal was one of the primary links between Angkor and Lake Tonle Sap which supplied water to the empire and Buckley et al conclude that this is evidence of the devastating impacts climate change had on the empire.

On top of devastating impacts of climate on water supply, other economic, social and geopolitical factors were also at play. Buckley et al acknowledge these, which include growing conflict with the Siamese Kingdom of Ayuddhaya (which is often blamed as the cause of collapse) and the increasing importance of maritime trade which caused the Khmer empire to turn away from inland agriculture and increased integration with regional trade.

I will look into these other factors in my next few posts.

The Khmer Empire

The Khmer Empire was established in the early 9^th century (800 C.E.) and had collapsed by 1430s. It was once the largest empire in South East Asia and existed in what is now Cambodia.

The Khmer empire was an agriculturalist society and relied heavily on rice cultivation. The extensive rice irrigation network allowed rice surpluses which helped support a large population. The Khmer empire had a sophisticated irrigation and water storage system as well as stable trade connections.

A temple once used for worship now covered by trees, Angkor. 

Source: WanderingMee

Historical records become very sparse after the 1300s, however we know that no large temples or monuments were erected after this period. Widespread abandonment of the Khmer Empire occurred roughly around this time. Some records attribute this decline to an invasion of the Thai army. Check out Plubins, 2013 for the Ancient History Encyclopedia. This is a good article for background knowledge, however I think it relies too heavily on the Thai army as an explanation.

It’s thought that one line of kinds remained in Angkor, the centre of the Khmer empire, while other kings moved to Phnom Penh. Gradually the economy was transferred to the new kingdom in Phnom Penh and therefore so did political power. This is thought to have led to the collapse of the Khmer empire in combination with conflicts within the royal family and Phnom Penh becoming the new centre of trade (New World Encyclopaedia).

However, recently other theories have emerged. The first to be looked at will be the role of climatic change which I’ll cover in my next post.

Things are not always as they seem

So we've looked at the main theories behind the collapse of the Rapa Nui of Easter Island. I think it's fair to say that there is little consensus as to what actually led to the decline of this culture.

Rather than hypothesize about possible triggers behind their decline, Bower (2014) has developed all of these ideas and takes an alternative approach. Bower argues that maybe the case of Easter Island shouldn't even be considered as an example of collapse.

Source: Harris, Cartoonstock

He stresses that unlike other articles, such as Mann et al (2008) from my previous post, deforestation does not equal societal collapse and correlations must not be confused for causation. He points out that, contrary to popular belief, the Rapa Nui civilization did not implode and disappear before European colonization in 1722. In fact the Rapa Nui society persisted at a constant level until 1774 when the culture declined. This decline is thought to have been caused by diseases introduced to the Island by European colonizers. Agriculturalists adapted to deforestation and the decrease in palm trees by turning to yam and sweet potato cultivation. Clever methods to reduce wind damage to small plants and reduce rain-water evaporation were developed, such as enclosing agricultural areas with rocks. This also deterred weed growth and improved soil nutrients.

Bower states that "the social collapse of the Rapa Nui has long been assumed, but there is so scientific evidence to support this". This demonstrates that the finer details need to be looked at when it comes to civilization collapse - things are not always as they seem!

Source: WorldlessTech                                                           Source: The Daily Omnivore

Something else that isn't what it seems - the Moai aren't just statues on the surface but have large bodies that are buried deep in the ground!

Next time I'll be introducing my final case study.

Merry Christmas!!