On account of its beauty, perfection and rarity – there are less than 70 pieces in the world - the “ru” celadons are considered the most precious of the ceramics and remain as the maximum expression of the art of the Chinese ceramist.

 

The “ru”, together with the “jun”, “ding”, “guan” e “ge”, make up the five classical types of ceramics of the Song era (960 -1297).

 

Produced in the neighborhood of the city of Ruzhou, in the province of  Henan, in the short period of two decades (from 1086 to 1106), exclusively  for imperial use and by recommendation of the Emporor and esthete Song Huizong (he reigned from 1101–1125), the “ru” stoneware stand out by their austere and elegant forms, the subtlety of their green-bluish glaze and by the total absence of decoration

 

The “ru” ceramics already were very valuable and scarce even during their period of production. Differently from other types of ceramics, the pieces were produced in smaller quantities, and then they were carefully selected and destined exclusively for the court. Those with unsatisfactory finishing were normally destroyed, never sold to someone else. 

 

The forms of the "ru" ceramics were inspired by objects of daily use: plates, bowls, vases, bottles, saucers, censers, pots for floats, etc, and had a notorious resemblance to fine products in lacquer of the same period. 

 

It is known that the pieces were ordered and used by the Emporor Song Huizong himself.

 

In the universe of ceramics, the “ru” is a type of stoneware with glazing known as “celadon”.  The body of the pieces - grayish-beige in color - is characteristically very thin and the glazing is thick. The temperature of the oven was slightly lower than for the other stoneware, that is between 1200 to 1250° C.

 

The type of oven used were the “mantou”, typical of the north of China. These ovens in circular form were so-called because of their resemblance to a type of homonymous bread. The “mantou” are small – no larger than 1,95 m in length – and do not allow for a large number of pieces at each heating.  

 

At the end of the XI century, coal was widely used in China as a form of fuel in the ceramic industry. Despite this, in the “ru” ovens, they preferred to use wood as in the old days. The logs were dearer, but better for controlling the very low levels of oxygen needed to reach the atmosphere for reduction. The name “celadon” very probably was derived from a French novel from 1627, by Honoré D’Astrée that was very successful in the XVIII century. In the novel, one of the characters always wore green and was called “Celadon”.

 

Technically, it is a glazing that contains from 2 to 3 % of ferrous oxide, which, upon being baked in a reduction atmosphere, reacts by taking on a green-bluish tone which is characteristic of that resembles that of jade. It is precisely this resemblance to jade that makes the “celadons” so appreciated in China and other countries of the East.  

In the sole case of the “ru”, agate powder was added to the glaze mixture, imbuing it with a very special tone and a subtle sparkle when placed against the light. In fact, the color of the pieces is perhaps their greatest beauty attribute. 

 

When observed close up, the “ru” possess thin uniforms cracks, which resemble glass broken into miniscule particles. These cracks are produced when the part is withdrawn from the heat of the oven and exposed to the colder room temperature. With the cooling, the glazing shrinks more than the body of the ceramic itself thereby causing a generalized and uniform fragmentation. This effect was and still is today greatly appreciated and sought after by ceramists and lovers of ceramics, mainly in China. So much so that they went so far as to cool briskly the pieces soon after the baking in order to obtain such cracks.  

 

Another characteristic of the “ru” is that the pieces are covered by the tonality of the glazing. Differently from other ceramics, where the support base stays uncovered and the body can be seen, the “ru” show a perfect finishing, with complete covering. This they managed to achieve by taking each piece to the oven perched on thin supports, thereby avoiding contract of the base with any surface.  

 

The National Palace Museum in Taipei, that possesses the largest collection of “ru” with 22 pieces, when it shows them, is accustomed to supporting them on glass stands and them putting them under a mirror placed at an angle of 45°, in order to allow the observer to appreciate the fine finishing of the lower face. One can then see the miniscule marks of the supports used at the time of baking, in the form of a sesame seed. 

 

Song Huizong , who certainly sponsored the production of the “ru”,  was the Emperor of the China with the greatest artistic talents. Apart from being an esthete, he was an excellent calligrapher, painter, poet, music lover and an avid collector of antiquities. His collection of paintings surpassed 6,000 in number, according to what is in the catalogues. His court was overflowing with luxury and good taste. 

Nonetheless, he reigned at a historic moment when China found itself surrounded and threatened on its Northern frontiers. Huizong did not know how to deal with external problems.

 

Bit by bit, China was losing its northern territories to the semi-nomadic Khitan, people of Liao dynasty. The military costs of defending the frontiers caused an increase in taxes, inflation and rebellions.

Committing a large error, Huizong allied himself with the Jurchen of the neigboring Jin dynasty to combat the Khitan. However, the ally tricked him and became an enemy. The Jurchen Jin invaded Chinese territory in 1125. Huizong abdicated in favor of his son Qinzong, who reigned for a short period in 1126. In this same year, the Jurchen took the capital Kaifeng. Huizong, his hier Qinzong and more than 3.000 constituents of the imperial court were captured and taken to the north as prisoners. Huizong died in prison in1135.

 

The ninth son of Huizong gives continuity to the imperial house and inaugurates the Song of the South dynasty in1127, setting up his court in the city of Hangzhou, on the banks of the Yangtze River. The ceramics for serving the court start to be made in the south of China and possess different characteristics from those of the north.

 

In spite of the “ru” being kept in collections during all these centuries, it is not known with certainty where the ovens were situated. The reason may have been the difficult times and the small scale of production.

 

It was always thought that the “ru” had been made in Kaifeng, in the very capital of the Song of the North dynasty, in the neighborhood of the imperial court.

 

Only in 1986 was the production site discovered near the small village of Qingliangsi, in the district of Baofeng, in the province of  Henan.

 

Because of the elevated status that the “ru” celadons enjoy in the history of world ceramics, this archeological discovery was much celebrated and permits the study of the production of the pieces.