I haven’t been doing research lately, but here are some excerpts I typed up a while back, from Willem A. Grootaers’ “Rural Temples around Hsüan-Hua (South Chahar), Their Iconography and Their History.” The field research was conducted in 1948, the article was published in 1951. Hsüan-Hua (Xuanhua) is located northwest of Beijing, in Hebei Province.
My apologies for the poor quality of the images: they are, of course, scans of copies of the photographs that Grootaers (or his assistants) took in 1948. The following quotes concern the worship of the Dragon King, Long Wang. Any emphasis added is mine.
First, a quote concerning the importance of the cult:
If the Wu-tao temple is the most popular, the Lung-wang temple is by its size and by the wealth of its images and of its lateral buildings (except for a few Buddhist monasteries) by far the most important temple of the region.
Therefore it is often chosen to be the seat of the official administrations recently introduced in village life: mayor’s office, primary school. It fulfilled a similar role, with greater influence even, under the Empire […]
The Lung-wang cult has always its own temple, this god being never used as an attendant image of another cult. (26)
There are certain patterns as to the temple’s location within the village:
In all villages of the Liu-ho plain, the Lung-wang temple is built in the southern part of the village, either southwest or southeast […] of the village.
But in the southeastern part of Hsuan-hua and in the south of Kalgan, the same temple is mostly (with half a dozen exceptions) north of the village.
This may be something similar to the case of the Lung-wang temples in Tatung, where the two types: southeast- northwest are separated by a clear boundary. (27)
Perhaps these arrangements have something to do with fengshui? They certainly don’t seem random.
Much better for our purpose [of determining historicity – HC] is the stone slab standing […] in what is now a school, and was till lately a Hu-shen temple. The stone is entitled: “ To commemorate the restoration of the Lung-wang sanctuary of Ning-yuan-pu 寧違堡 in 1493.”
The text goes on: “Ning-yuan is about 40 li northwest of Hsuan-hua; another day travel towards the west, there is a high mountain with a grotto. In this grotto a statue of the Dragon god was suspended by means of iron chains […] the statue had the date: first year of Chih-cheng 至正, 1341.
In the years of Yung-lo 永 樂 (1368-1398), a peasant gathering firewood on the mountain saw a heavenly manifestation…thereafter the people […] used to offer there incense on the 15th day of every moon…In the year 1470 there was a temple to this god in our village. Now we have been restoring it, the western building being a Lung-wang sanctuary, the eastern one a Tzu-sun 子孫 temple.”
The mountain indicated here is rather in a northwesternly direction, and was a favorite spot for pious pilgrims till the first year after World War II. The various temples on the slopes were then levelled by the Nationalist Army and the whole transformed into an advanced defense position, for the city of Kalgan.
This dated and detailed witness of the Lung-wang cult is the earliest yet noted in our travels. One must note the recurrence of the grotto motive in another Dragon King cult. (28)
The 15th day of every moon is, of course, the full moon. I’m not sure if the iron chains have any particular significance, but Grootaers is clear that “one must note the recurrence of the grotto motive in another Dragon King cult” (28).
There are actually multiple dragon kings, and they are often accompanied by their Mother:
Till now we have always spoken of the “ Dragon King”; this is a simplification, there being in reality at least four Dragon Kings, sitting on each side of the Mother of the Water, Shui-mu 水母.
There is a great variety possible in depicting each individual Dragon King. They are mostly distinguished by the colour of their face […]
Their number may vary from two to twelve; nobody could ever tell us whether they are supposed to have a name. The popular tradition in Hsuan-hua is definite however on one score: they are all the sons of the Mother of the Water.
Dragon King face colors include white, red, yellow and black. The Mother of the Water is usually white-faced, but in two villages her face is gilded. (29)
I find it interesting that the individual Dragon Kings may or may not have names. I’m not sure what exactly I should extrapolate from this fact, though. Perhaps a value of title and function over individual identity? That’s certainly an idea I’ve come across before, when I was researching the various local land gods, all known as Tu Di Gong.
In one case […] two Mothers were found, side by side, in the center, each having six Dragon Kings along her side of the wall. […]
A Male Dragon occupies the central place in six villages. There seems to be hardly any relation between this god and the Mother of the Water.
There remain four more villages […] where a sole white-faced Dragon King occupies the place of honor (see fig. 10 [above]), the temple being each time called Lung-wang temple. That is the reason why we hardly could list them under chapter 2b, which describes a White Dragon cult […] The latter is clearly considered as something quite distinct from the Lung-wang cult by the local people. […]
At Dv 176, the Lung-wang temple has all the normal features of such temples, except for the fact that they put a statue of the Ho-shen god of the river […] in the center, around which the usual Dragon Kings are ranged.
A last, but more important discrepancy was found at Dv 163a […] two of the Kings have the head of a Dragon on the body of a man. This is specially significant, as the Lung-wang in Peking and in other parts of Hopei is always represented under that shape (even the Mother of the Water is completely unknown in those regions). We have here probably the second indication hinting at an influence of eastern forms of worship that seep in to the Hsuan-hua region. (29-31)
We can see from these numerous examples that local variation is actually very common, which is a good reminder that the generalizations that Grootaers comes to regarding forms of worship in Xuanhua do not necessarily apply to other regions of China.
As we have explained in the beginning of this part both extremities of the main wall, especially in the Lung-wang temple are reserved for separate cult units. Their independence of the central image is stressed by the presence either of a painted partition between the images on the wall, or even by some wooden scrollwork which divides the temple into separate cubicles.
These lateral images have often their own heavenly court, grouped around them, with all their own paraphernalia of the cult. However some tenuous relation must exist between them and the cult of Lung-wang as not all gods may possibly occur in that place, but only a few, always the same. (31)
The most common is Ma Wang (the Horse God), who occupies this position in 39 out of 49 temples, which is more than twice as many as the god with the second-most number of lateral images (the aforementioned Ho-shen river god, image above). Given my previous post about Ma Wang, I’m very curious as to the roots of this association.
The most striking likeness with our frescoes however was found in some paintings of the Sung dynasty (960-1280) of the Museum of Fine Arts, Boston, Mass. Their title is given as Chinese Taoist Pantheon, deities of Heaven, Earth and Water. […] The painting of the God of the Water is the direct ancestor of our Lung-wang frescoes.
The god, riding on a dragon on top of clouds beneath which some roofs are visible, is accompanied by attendants among whom we find many familiar personages: the pursuing devil in the lower part, the two genii sitting on a turtle (corresponding to our genii riding on fishes), the thunder god in the top left corner, with his wheel of drums; even the flag held behind the head of the god. (37)
I don’t see all of the listed elements on the fresco I’ve included above, but perhaps you have a better eye?
As to what conclusions (if any) can or should be drawn from this research, I don’t know. That’s up to you, I suppose.