Complex sentence: An older man (he is called "Gamling the Old"), he was from the Westfold, and understood the language of Dunland, and he was familiar with the hatred that the Dunlendings had for the Rohirrim.
Split into simpler sentences: An older man (he is called "Gamling the Old"), he was from the Westfold. He understood the language of Dunland and was familiar with the hatred that the Dunlendings had for the Rohirrim.