| Year | Event |
| c.400 BC | Gautama 'Buddha' founds Buddhism |
| 333 BC | Persian rule in the northwest ends after Darius III is defeated by Alexander the Great. Alexander had established the Macedonian Empire after inheriting the Persian Achaemenid Empire. |
| 326 BC | Ambhi, king of Taxila surrenders to Alexander. Porus who ruled parts of the Punjab, fought Alexander at the Battle of the Hydaspes River. |
| 321 BC | Mauryan Empire is founded by Chandragupta Maurya in Magadha after he defeats the Nanda dynasty and Macedonian Seleucid Empire. Mauryan capital city is Patliputra (Modern Patna in Bihar) |
| 305 BC | Chandragupta Maurya defeats Seleucus Nicator of the Seleucid Empire. |
| 304 BC | Seleucus gives up his territories in the subcontinent (Afghanistan/Baluchistan) to Chandragupta in exchange for 500 elephants. Seleucus offers to marry his daughter to Chandragupta to seal their friendship. |
| 273 BC | Ashoka the Great, grandson of Chandragupta Maurya, ascends as emperor of the Mauryan Empire. |
| 266 BC | Ashoka conquers and unifies most of South Asia, along with Afghanistan and eastern Iran. |
| 265 BC | Kalinga War takes place. After conquering Kalinga, Ashoka regrets the killings in the war, leading him to adopt Buddhism, which then became the quasi-official state religion of the Mauryan Empire. |
| 260s | Ashoka begins displaying religious tolerance, grants animal rights, builds hospitals for people and animals, treats his subjects as equals regardless of caste or creed, and promotes non-violence and republicanism. Ashoka inscribes the Edicts of Ashoka, written down using Brahmi script. |
| 232 BC | Ashoka dies and is succeeded by Kunala. |
| 230 BC | Simuka declares independence from Mauryan rule and establishes the Satavahana Empire. |
| 200 BC | Kuninda Kingdom established. |
| 200-100 BC | Tholkappiyam describes the grammar and morphology of Tamil; it is the oldest existing Tamil grammar (dates vary between 200 BCE and 100 CE). |
| 184 BC | The Mauryan Empire, which shrunk considerably, collapsed after its emperor Brihadrata was assassinated by his general Pusyamitra Sunga who then established the Sunga dynasty. |
| 180 BC | Establishment of the Indo-Greek kingdom. |
| 80 BC | Establishment of the Indo-Scythian kingdom. |
| 65 BC | The Pandyan king sends ambassadors to the Greek and Roman lands. |
| 57 BC | Beginning of Vikram Era |
| 10 AD | Establishment of the Indo-Parthian kingdom. |
| 68 AD | Establishment of the Kushan empire by Kujula Kadphises. |
| 78 AD | Gautamiputra Satkarni becomes Satavahana emperor and starts Shalivahana era calendar after defeating Scythian king Vikramaditya. |
| 35 AD | Western Satraps formed. |
| 240 AD | Sri-Gupta starts the Gupta Empire in Magadha, with its capital in Patliputra |
| 320 AD | Chandragupta I ascends to the Gupta throne. |
| 335 AD | Samudragupta ascends the Gupta throne and expands the empire. |
| 380 AD | Chandragupta II, Samudragupta's son becomes the Gupta Emperor. |
| 450 AD | Invasions by the Huna. |
