Most invasions occurred during favourable monsoons in India: Study

The study revealed that eight out of 11 major invasions between the 6th century BCE (before common era) and 16th century CE (common era) occurred during good Indian monsoons

Exploring the potential correlation between long-term climatic events and major invasions in the Indian subcontinent, scientists from the Indian Institute of Tropical Meteorology (IITM) Pune have found that climate played a crucial role in the historical invasions, and favourable climatic conditions made the region an attractive target for external forces seeking wealth and control.

Moreover, the presence of trade routes further facilitated invasions by providing access to valuable resources. (HT PHOTO)

The study revealed that eight out of 11 major invasions between the 6th century BCE (before common era) and 16th century CE (common era) occurred during good Indian monsoons. Moreover, the presence of trade routes further facilitated invasions by providing access to valuable resources.

The research team comprised scientists from IITM Pune and the Department of Remote Sensing, BIT (Birla Institute of Technology), Mesra, Ranchi, namely Smruti Sardar, Protyusha P Mukhopadhyay and Parthasarathi Mukhopadhyay among others. The study was led by Naveen Gandhi, a senior scientist from IITM. It was published recently in the first week of April in the Journal of Earth System Science.

The scientists discovered that with the exception of two instances, all major invasions from central Asia occurred during favourable monsoon conditions in the Indian subcontinent and unfavourable climatic conditions in central Asia. Only Alexander the Great and Timur invaded India during unfavourable monsoon conditions. The primary objective of these two invasions was global conquest rather than immediate economic/strategic interests and hence, they may be considered different from the rest.

The study revealed that almost every invasion between the 6th century BCE and 16th century CE was associated with a special monsoon climate. For instance, the invasion by Cyrus II coincided with a prolonged good monsoon in India and drought conditions in central Asia. Alexander the Great invaded India during a weak monsoon and drought conditions here. Looking at history, Alexander’s invasion of India is often seen as following in the footsteps of Greek rulers such as Cyrus the Great, Dionysus and Hercules. However, his unwavering ambition might have been the most significant driving force behind his campaign, regardless of the monsoon conditions in India.

Furthermore, the Hunas invasion occurred during a favourable monsoon in the Indian subcontinent and weaker precipitation in the central Asian (steep) regions. Similar trends were seen in both India and central Asia when Muhammad Ibn Al-Qasim, a military commander under the Umayyad Caliphate, invaded the Chacha Empire in Sindh. When drought conditions persisted in central Asia from 950 CE to 1025 CE, a very strong and favourable monsoon was observed in the Indian region, coinciding with the infamous repeated plundering of the temple towns of Mathura and Somnath by Mahmud of Ghazni.

The favourable Indian monsoon conditions from 1220 CE to 1270 CE coincided with weak precipitation in central Asia. This period involved a series of battles fought between Mohammad of Ghori and Prithviraj Chauhan III. Although the monsoon was weak in India from 1190 CE to 1210 CE in India, Bakhtiyar Khilji, a Turkic military general of the Ghurid Empire, invaded India multiple times between 1197 and 1206 CE. Genghis Khan and Alauddin Khilji invaded India during a good monsoon and abundant rainfall. Timur, a Turko-Mongol conqueror, invaded India during weak monsoon conditions. After his conquest of the whole of central Asia up to Moscow, Timur turned towards the east and in 1398, decided to invade India in his desire for global conquest rather than immediate economic or strategic interests, akin to Alexander the Great. Babur’s invasion in the 16th century CE coincided with excellent monsoon conditions in India.

The study offered valuable insights into the historical dynamics of the Indian subcontinent by understanding the intricate relationship between climatic conditions, trade networks and invasions. It underscored the interdependencies between natural processes, human societies, and the impact of climate on socio-political landscapes. Moreover, it highlighted the significance of climatic factors when examining historical invasions, said Naveen Gandhi.

Methodology

For this study, past climate data was selected based on various criteria. The scientists chose a tree ring record from 1484 CE to 2003 CE from Kerala, which provides annual resolution records of monsoon precipitation. Beyond 1484 CE, they utilised oxygen isotope records (2014 CE to 1293 BCE) from cave deposits (speleothems) in central and peninsular India. Similarly, they employed oxygen isotope records covering the last 10,000 years from cave deposits in central Asia.

Further direction of research

Speaking about the next step in research, Gandhi said, “We are extending our research to the newly discovered Harappan metropolis of Rakhigarhi, Haryana, aiming to uncover the climatic conditions during the settlements’ early and mature phases. Our objective is to determine the precise factors contributing to the collapse of the civilisation. Additionally, we seek to elucidate the influence of climatic variations on Indian culture, civilisation, historical events, and evolution across different regions of India over the past 10,000 years.”