Hi Ann,
In Elgood’s book ‘Hindu Arms and Ritual’, page 301, note 9 under ‘Glossary’ he writes, ‘Java lay on the sea route between China and Iran. Trade was extensive during the Song dynasty (960-1270) and reached its peak during the Yuan dynasty (1271-1368). Many Persians settled the southeast coast of China and there was considerable sea trade with Hormuz until the Ispha (Persian, ‘large army’) rebellion of 1357-66 in Fujian, after which the Muslims fled or were killed.
Here Elgood tells about early sea trade routes, and in addition to the sea trading the caravans also traded a lot, especially the ones on the Silk Road, and the caravans going further into the countries, and like you say, good steel has always been a good thing to bring along for trading.
Nice Bolo and nice blade

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All the best with your 'lecture'

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Jens