The sultanate of Melaka (OTL Malacca) was founded ~1400. 1400-02, it was visited by Chinese Treasure Ships on their first voyage. Chinese influence entered Melaka. 1408 (3105, Yang Earth Rat in the Chinese calendar), the ruler of Melaka married a Chinese noblewoman, started paying a small tribute to China. This was one of many signs of the cultural changes brought to SE Asia by the Chinese.
When in the 1420s Civil War broke out in Majapahit, China intervened here. By playing out the empires of Melaka and Majapahit against each other, they put sure that neither gained the upper hand.
1539/40, Melaka attacked Aceh with Chinese help, annexing it.
In 1731, after the power of Hong China had declined, France founded the Indochinese League with Bengal, Pegu, Thailand, Khmer, Champa and Melaka. One year later, they founded Fort Knox at the site of OTL Singapore, to control the area better.
After France became a republic, the League fell apart. Instead, in 1783 Italy made a trading treaty with Melaka.