The largest imperial seal used by Chinese Emperor Kangxi, who ruled China from 1661 to 1722, went under the hammer in Hong Kong on 6 April and fetched $11.8m (£8.41m). Sothebys said an Asian buyer won the bid and that it set the third highest price for any Chinese imperial seal sold at auction.

These objects are very, very hard to price, because youre not really selling the physical object as it is, youre not selling a piece of wood, youre selling the symbolism of the seal. So its always very hard to gauge how much it will fetch. $12 million is an extraordinarily strong price for an object like that, Deputy Chairman of Sothebys Asia and International Head of Chinese Works of Art, Nicolas Chow, said.

The seal was described by Sothebys as the most important Chinese historical object ever to be offered at auction.

Well this is the largest seal ever carved for Emperor Kangxi, who was the longest reigning monarch in the history of China. The four characters on the base say jingtian qinmin which means revere heaven, and serve thy people. It really crystallises the political theory in China whereby heaven bestows its power upon the ruler who is righteous and benevolent. What it really says is, I revere heaven, Im righteous, I serve my people well, therefore I am the legitimate ruler of this country, Chow said.

The pig dragon on the seal, a supernatural beast, symbolises the link between heaven and earth, Chow added. Among the other top lots, a blue and white moon flask from the Yongle Emperor period (1403-24) sold for $14.2m, while a white and blue holy water vessel from the same period fetched $12.7m

Sothebys Spring Sales ended on 6 April, while its rival Christies is hosting their spring auctions from 27 May to 1 June.