Ancient Chinese-Khotanese relations were so close that the oasis emerged as one of the earliest centres of silk manufacture outside China. There are good reasons to believe that the silk-producing industry flourished in Hotan as early as the 5th century. According to one story, a Chinese princess given in marriage to a Khotan prince brought to the oasis the secret of silk-manufacture, "hiding silkworms in her hair as part of her dowry", probably in the first half of the 1st century CE. It was from Khotan that the eggs of silkworms were smuggled to Iran, reaching Justinian I's Constantinople in 551. Silk production is still a major industry employing more than a thousand workers and producing some 150 million metres of silk annually. Silk weaving by Uyghur women is a thriving cottage industry, some of it produced using traditional methods. Hotan Silk Factory is one of the notable silk producers in Hotan.