Re: History of Pakistan
Hope book has Chankya, the main person, he bought chandragupta from slave market for four gold coins, took him to Taxila and made him emperor by dislodging Nanda empire. Chandragupta invaded Selucus necator in Punjab and his daughter Princess Helena became Chandragupta’s wife 
Yes, the rivalry was very bitter, it has famous battle of Thermopylae