At the time of Alexander`s invasion, India was divided into many kingdoms. In the middle of India was the big empire of Magadha but in the northwest of India there were many small kingdoms as well. A constant rivalry and warfare went among these states. Besides division and dissension, Persian invasions had further weakened these states. Some of these states were monarchies while other were republics. The names of the states, which existed at the time of invasion of Alexander, can be mentioned as Aspersion i.e. North of Kabul, The country of the Guraeans situated between the land of the Aspasian and Assa Keniaus, The kingdom of Assakenos placed at the East of river Indus, Nysa situated in between river Kabul and river Indus, Penkelaotis situated at the west of Gandhara, Taxila situated between river Indus and Jhelum, The kingdom of Arskes situated near district of Hazrra, Abhisara placed at Western portion of Kashmir, The kingdom of elder Paros situated between Jheulm and Chenab, Glanganikai situated at the west of Chenab. The Adraistai i.e. territory east of Ravi, Kathalio situated between Jhelum and the Chenab, The kingdom of Sophytes placed on the bank of river Jhelum, The kingdom of Phegelas situated between river Ravi and Bias), The Siboi placed between river Jhelum and Chenab, Agalassoi situated near kingdom of Siboi, Mallbi situated at the right bank of river Ravi, The oxy-erakai or Kshudrakas placed near Siboi and the Agalassoi, The Abastanoi situated near Malva country, The Xathaoi and Ossadioi placed between the confluence of river Ravi and Indus, The Sodrai and the Massanoi placed at Northern Sind, certain portion of the public and Bhawalpur state, The kingdom of Mousikanos i.e. Sindh, Principality of Orykanos situated West of Indus near Larkana district), The kingdom of Sambos placed near Indus and Patalene i.e. Indus delta.
Most of the above mentioned kingdoms were republics. There was no political unity in the northwestern portion of India as the constant water fare went on among the small kingdoms. These were the conditions of India on the eve of the Alexander`s invasion and Alexander took advantage of such conditions very intelligently.