20th century BC

The 20th century BC is a century which lasted from the year 2000 BC to 1901 BC.

Events

Indus River

The Indus River, also called the Sindhū River, or Abāsīn, is a major south-flowing river in South Asia. The total length of the river is 3,180 km (1,980 mi) which makes it one of longest rivers in Asia. It flows through Pakistan, the Indian state of Jammu and Kashmir and western Tibet. Originating in the Tibetan Plateau in the vicinity of Lake Mansarovar, the river runs a course through the Ladakh region of Jammu and Kashmir, towards Gilgit-Baltistan and then flows in a southerly direction along the entire length of Punjab, Pakistan to merge into the Arabian Sea near the port city of Karachi in Sindh. It is the longest river of Pakistan.

The river has a total drainage area exceeding 1,165,000 km² (450,000 sq mi). Its estimated annual flow stands at around 207 km³ (50 cu mi), making it the twenty-first largest river in the world in terms of annual flow. The Zanskar is its left bank tributary in Ladakh. In the plains, its left bank tributary is the Chenab which itself has four major tributaries, namely, the Jhelum, the Ravi, the Beas and the Sutlej. Its principal right bank tributaries are the Shyok, the Gilgit, the Kabul, the Gomal and the Kurram. Beginning in a mountain spring and fed with glaciers and rivers in the Himalayas, the river supports ecosystems of temperate forests, plains and arid countryside.

Indus Valley Civilisation

The Indus Valley Civilisation (IVC) was a Bronze Age civilisation (3300–1300 BCE; mature period 2600–1900 BCE) extending from what today is northeast Afghanistan to Pakistan and northwest India (see map). Along with Ancient Egypt and Mesopotamia it was one of three early civilisations of the Old World, and of the three the most widespread. It flourished in the basins of the Indus River, one of the major rivers of Asia, and the Ghaggar-Hakra River, which once coursed through northwest India and eastern Pakistan.

At its peak, the Indus Civilisation may have had a population of over five million. Inhabitants of the ancient Indus river valley developed new techniques in handicraft (carnelian products, seal carving) and metallurgy (copper, bronze, lead, and tin). The Indus cities are noted for their urban planning, baked brick houses, elaborate drainage systems, water supply systems, and clusters of large non-residential buildings.

List of Indian inventions and discoveries

This list of Indian inventions and discoveries details the inventions, scientific discoveries and contributions of ancient and modern India, including both the ancient and medieval nations in the subcontinent historically referred to as India and the modern Indian state. It draws from the whole cultural and technological history of India, during which architecture, astronomy, cartography, metallurgy, logic, mathematics, metrology and mineralogy were among the branches of study pursued by its scholars. During recent times science and technology in the Republic of India has also focused on automobile engineering, information technology, communications as well as research into space and polar technology.

For the purposes of this list, inventions are regarded as technological firsts developed in India, and as such does not include foreign technologies which India acquired through contact. It also does not include technologies or discoveries developed elsewhere and later invented separately in India, nor inventions by Indian emigres in other places. Changes in minor concepts of design or style and artistic innovations do not appear on the list.

Outline of ancient India

The following outline is provided as an overview of and topical guide to ancient India:

Ancient India – India as it existed from the pre-historic times (c. 7000 BCE or earlier) to the start of the Middle Ages (c. 500 CE).

Geography of ancient India

Government and politics in ancient India

General history of ancient India

Periodisation of Indian history

An elaborate periodisation may be as follows: