Thus began the Malayalam Era, known as Kolla Varsham after the city, indicating the importance of Kollam in the 9th century. The Persian merchant Soleyman of Siraf visited Malabar in the 9th century and found Quilon to be the only port in India used by the huge Chinese ships as their transshipment hub for goods on their way from China to the Persian Gulf. The rulers of Kollam (formerly called 'Desinganadu') had trade relations with China and exchanged embassies. According to the records of the Tang dynasty (618–913), Quilon was their chief port of call before the 7th century. The Chinese trade decreased about 600 and was again revived in the 13th century. "Mirabilia Descripta" by Bishop Catalani gives a description of life in Kollam, which he saw as the Catholic bishop-designate to Kollam, the oldest Catholic diocese in India. He also gives true and imaginary descriptions of life in 'India the Major' in the period before Marco Polo visited the city.