Complex sentence: When Samoothiri of Calicut became a major force on the western coast, they captured a large portion of Valluvanad and the right of Mamankam was usurped by Samoothiri, when he captured the town in the latter half of the 13th century by Thirunavaya Wars.
Split into simpler sentences: When Samoothiri of Calicut became a major force on the western coast, they captured a large portion of Valluvanad. This right was usurped by Samoothiri, when he captured the town in the latter half of the 13th century by Thirunavaya Wars.