After the fall of the mighty Mauryan Empire different foreign horde came to India. No doubt they came as aggressors.
But in course of time they very much became a part of the Indian society and culture by adopting Indian way of life.
Of the foreign invaders in the pos Mauryan period mention may be made of the Indo-Greeks, also known as the Bactrian Greeks. Menander was the most prominent of all the Bactrian kings.
After the Indo-Greeks came the Sakas or the Scythians. The Sakas established a small but powerful kingdom in India.
The Sakas invaded the Gupta Empire. Next come the Parthians or Pahlavas.
The Pahlavas ruled in western Punjab. The Kushanas were the only foreigners who established an empire India.