Sentence:  In 326, after fighting his way across the various regions and tributaries of the upper Indus or Punjab as far as the <WSD>Hydaspes</WSD> River, Alexander encountered Porus, the king of the region between the <WSD>Hydaspes</WSD> and the Acesines (Chenab) rivers. 
Meaning of the word marked with <WSD> tags:  The river Jhelum, on the Indian subcontinent, especially as the location of a battle fought by Alexander the Great against King Porus in 326 BCE.