Complex sentence: Although Sindok establishes a new dynasty, the Isyana dynasty named after his daughter, Sindok seems to be closely related to the royal house of Medang Mataram, thus he can be viewed as the continuation of a long line of Javanese Kings lineage stretched from King Sanjaya.
Split into simpler sentences: Although Sindok establishes a new dynasty, the Isyana dynasty named after his daughter, Sindok seems to be closely related to the royal house of Medang Mataram. He can be viewed as the continuation of Javanese Kings lineage stretched to King Sanjaya.