Complex sentence: While still living in the area of Fang he was visited by some merchants from the Mon kingdom of Haripunchai (Haripunjaya, now known as Lamphun); hearing of the wealth of that kingdom he determined to conquer it, even against the advice of his counselors.
Split into simpler sentences: While still living in the area of Fang he was visited by merchants from the Mon kingdom of Haripunchai (Haripunjaya, now known as Lamphun). Hearing of the wealth of that kingdom, he determined to conquer it, against the advice of his counselors.