The Indus Valley Civilization, Pakistan
Home to one of the greatest man-made architectural wonders of the ancient world, the Indus Valley Civilization (known at the height of its influence as the Harappan Civilization) was among the largest early urban settlements on any continent. Located in modern-day Pakistan, the Indus Valley Civilization thrived 4,500 years ago and was then forgotten but for local legends until ruins were excavated in the 1920s.
Sophisticated and technologically advanced, this civilization, including the famous Mohenjo Daro, featured the world’s first urban sanitation systems as well as evidence of surprising proficiency in mathematics, engineering and even proto-dentistry. By the year 1500 BCE, the Indus Valley Civilization was virtually abandoned, possibly after invasion by Indo-European tribes or a collapse in agriculture due to climate change.
The Khmer Empire, Cambodia
Once one of the most powerful empires of Southeast Asia, the Khmer civilization spread from modern-day Cambodia out into Laos, Thailand, Vietnam, Myanmar and Malaysia and is best known today for Angkor, its capital city. The empire dates back to 802 CE. Other than stone inscriptions, no written records survive, so our knowledge of the civilization is pieced together from archaeological investigations, reliefs in temple walls and the reports of outsiders including the Chinese.
The Khmers practiced both Hinduism and Buddhism and built intricate temples, towers and other structures including Angkor Wat, dedicated to the god Vishnu. Attacks from outsiders, deaths from the plague, water management issues affecting the rice crops and conflicts over power among the royal families likely led to the end of this empire, which finally fell to the Thai people in 1431 CE.
The Aksumite Empire, Ethiopia
A major participant in trade with the Roman Empire and Ancient India, the Aksumite Empire – also known as the Kingdom of Aksum or Axum – ruled over northeastern Africa including Ethiopia starting in the 4th century BCE. Theorized to be the home of the Queen of Sheba, the Aksumite Empire was likely an indigenous African development that grew to encompass most of present-day Eritrea, northern Ethiopia, Yemen, southern Saudi Arabia and northern Sudan.
The empire had its own alphabet and erected enormous obelisks including the Obelisk of Axum, which still stands. It was the first major empire to convert to Christianity. Axum’s decline has been variously blamed on economic isolation due to the expansion of the Islamic Empire, invasions, or climate change which altered the flood pattern of the Nile.
The Nabateans, Jordan
The ancient Nabatean civilization occupied southern Jordan, Canaan and northern Arabia starting in the sixth century BCE, when the Aramaic-speaking Nabatean nomads began gradually migrating from Arabia. Their legacy is epitomized by the breathtaking city of Petra, carved into the solid sandstone rock of Jordan’s mountains, and they are remembered for their skill in water engineering, managing a complex system of dams, canals and reservoirs which helped them expand and thrive in an arid desert region.
Little is known of their culture and no written literature survives. They were overtaken by the Romans in 65 BCE, who took full control by 106 CE, renaming the kingdom Arabia Petrea. Sometime around the 4th century CE, the Nabateans left Petra for unknown reasons. It’s believed that, after centuries of foreign rule, the Nabatean civilization was reduced to disparate groups of Greek-writing peasants who were eventually converted to Christianity before their lands were seized altogether by Arab invaders.
Moche Civilization, Peru
More of a collection of peoples that shared a similar culture than an empire, the Moche civilization developed an agriculturally-based society complete with palaces, pyramids and complex irrigation canals on the north coast of Peru between about 100 and 800 CE. While they had no predominant written language, leaving us few clues as to their history, they were an extraordinarily artistic and expressive people who left behind incredibly detailed pottery and monumental architecture.
In 2006, a Moche chamber was discovered that was apparently used for human sacrifice, containing the remains of human offerings. There are many theories as to why the Moche disappeared, but the most prevalent explanation is the effect of El Nino, a pattern of extreme weather characterized by alternating periods of flooding and extreme droughts. Perhaps this explains the Moche’s bloody efforts to appease the gods.