Complex sentence: The first historically significant king of this dynasty was Vivaswan's grandson Ikshvaku (इक्ष्वाकु), so the dynasty is also known as the Ikshvaku dynasty.
Split into simpler sentences: The first historically significant king of this dynasty was Vivaswan's grandson Ikshvaku (इक्ष्वाकु). The dynasty is also known as the Ikshvaku dynasty.