"Golden Sunset Over Ha Long Bay" by painter Pham Hau. (Photo courtesy of Bonhams)

Pham Hau’s work, once belonged to King Bao Dai, was auctioned at a "Southeast Asian Modern and Contemporary Art" sale by Bonhams, an international auction house.

It was the very first time that a documented painting from the king’s personal collection was offered at an auction.

The painting, never seen in public since it was created, is a six-panelled lacquer screen with dimensions of 100 x 195.8 centimeters. It depicts the landscape of Ha Long Bay, a UNESCO world heritage site in northeast Vietnam.