Final answer:
The Persian Empire was notable for minting coins, promoting learning, and setting up a postal system. Alexander's rule is remembered for attempts to unify India and opening of new trade routes. The Mauryan and Gupta Empires were instrumental in unifying India, promoting Buddhism, trade, culture, and setting up efficient governance systems.
Step-by-step explanation:
The achievements of various dynasties and rulers in ancient India can be attributed as follows:
- Persian Empire: Introduced the technique of minting coins and inscribing rocks, promoted Vedic and Iranian learning, and set up a postal system.
- Alexander's rule: Made the first attempt to unify parts of India, won the Battle of the Hydaspes, and opened a new water route along the Indus River and the Arabian Sea.
- Mauryan Empire: Succeeded in unifying much of India, strongly promoted Buddhism, and established a central government that allowed local rule.
- Gupta Empire: Revived trade along the Silk Road and on the Indian Ocean, reunited parts of India that had disintegrated after the Kushan rule, and was noteworthy for cultural and scientific advancements as evidenced by the presence of the Chinese pilgrim Xuanzang in Bamiyan during their rule.
The Mauryan Empire, founded by Chandragupta Maurya, was a significant force in unifying much of India and was also instrumental in spreading Buddhism under the reign of emperor Ashoka. The Gupta Empire, on the other hand, is known for a golden age of cultural and scientific achievements in India.