In 130 BC the Han Dynasty opened trade with the West, so this is considered the start date for the Silk Road and for truly global trade, but it had ancient origins even before that.
The Silk Road (a.k.a “Silk Routes” because it was actually many trails, not just one road) was a major trade route for over 1500 years until it was blocked by the Ottoman Empire in 1453 due to a blockade against China.
When I was in school they talked about Marco Polo and the Silk Road together, quickly and superficially, but the Silk Road was open for 1400 years before Marco Polo, a mercantilist from Venice, explored the entire Asian world visiting many countries as the foreign emissary of Kublai Khan for over 20 years, from 1269-1291, and wrote a book about it, “The Travels of Marco Polo”.
That book opened European eyes and culture to China and the “Far East”.
During that same time frame, the 13th Century, the Mongol Empire expanded dramatically, extending from the Sea of Japan to the Mediterranean Sea, the largest contiguous land empire in history. The Silk Road, therefore, was completely controlled by one empire during the travels of Marco Polo.
The key driver of this explansion was Genghis Khan, grandfather of Kublai Khan.