One theory is that the imperial court gave the surname of 'Uzumasa' with kanji characters meaning silk cloth, to the powerful Hata clan, who were immigrants, due to the silk clothes they used to pay as taxes to the Yamato Dynasty piling up in great heap.
渡来人の豪族秦氏がヤマト王権に税を納める際、用いた絹が「うずたかくつもられた」ことから、朝廷から「うずまさ」の姓を与えられ、これに「太秦」の漢字表記を当てたという説。