Short answers, pulled from the story.
The Indian Plate began its northward journey from ancient Gondwana roughly 50 to 55 million years ago. This massive landmass eventually collided with the Eurasian plate, creating the Himalayan range and the Tibetan Plateau.
By 2600 BCE, the Indus Valley Civilisation flourished in present-day Pakistan and North India. A sophisticated urban culture developed during the Mature Harappan period until 1300 BCE.
Muhammad bin Tughlaq came to power in 1325 and launched a war of expansion. His rule saw the largest geographical reach of the sultanate over the South Asian region.
South Asia contains about 2.04 billion people making it the most populated region in the world. It accounts for 25 percent of the world's population.
Sea level rise in Bangladesh will displace 0.9 to 2.1 million people by 2050. Around 2050, people living in the Ganges and Indus river basins may face severe water scarcity due to both climate and socioeconomic reasons.