While the history of Classical Buddhism in China dates to about 65 A.D., the history of Zen begins in about 475 A.D. when the monk Bodhidharma arrived in China. (Other sources cite different dates for Bodhidharma's arrival. The exact dates in antiquity may be happily quibbled among those to whom they are excruciatingly relevant.)

Some maintain that Bodhidharma came to China from Northern India. Others claim that Bodhidharma came from an area that would now be part of Iraq. Most of the canonical writings of Zen, however, simply state that Bodhidharma came to China "from the west." Among the classical philosophical questions of Zen (called "koans") is "What was Bodhidharma's purpose that he came from the west." (The answer to that one, by the by, is unknown and is considered by many to be about as relevant as "how many angels can dance on the head of a pin.")

The Buddhism that Bodhidharma brought to China parted from the Classical teachings of Buddhism in that Bodhidharma taught a "wordless transmission outside the scriptures." The teachings of Bodhidharma, in essence, maintained that the classical study of sutras (think "scriptures" for lack of a better word) was less relevant to enlightened understanding than was one's own innate understanding of the point and functional nature of the teachings themselves. Bodhidharma was of the Meditation (or "Dhayana") School of Classical Buddhism that placed high emphasis on meditation as the portal to enlightenment.

"Dhayana," by the by, is an important word for students of Zen. That word became "Ch'an" in Chinese and later morphed into the word "Zen" in Japanese when the Ch'an techings were introduced to Japan.

Both words, "Chan" in the Chinese and "Zen" in the Japanese, are pronunciations of the same "glyph," which is .

For the purposes of this "thumbnail" history, suffice it to say that the "patriarchs" of Ch'an / Zen who succeeded Bodhidharma were Hui K'o, who was further succeeded by Seng-Ts'an, Tao-hsin, Hung-jen, and then Hui-neng. There is also a bit of "palace intrigue" in China that placed Shen Xiu (aka: Hui-ming) as the "official" successor to Hung-jen, however, Hui Ming later recognized Hui Neng as the true patriarch as was the actual preference of Hung-jen.

By the time Hui Neng became the Sixth Patriarch of Ch'an, the school had divided between "Northern Ch'an" based in the North of China and heavily influenced by Confucianism and "Southern Ch'an" influenced by Taoism. With Hui Neng, however, Southern Ch'an became the ascendant teaching.

As noted in a good "thumbnail history" by academician Brett Greider, Ph.D., of the University of Wisconsin, Eu Claire: "Meditation has been an integral part of Buddhism from the beginning. Nevertheless, a school of meditation grew up in India and was taken to China by Bodhidharma about AD 520. When the meditation school arrived in China, it had a strong foundation on which to build: Taoism, the ancient Chinese religion. This religion is based on the idea that there is one underlying reality called the Tao. Taoists, like the followers of the meditation school, exalted intuition over reason. This Taoist tradition was easily absorbed by the Chinese meditation school, the Ch'an.

Within two centuries the meditation school had divided into two factions: Northern Ch'an and Southern Ch'an. The northern school, a short-lived affair, insisted on a doctrine of gradual enlightenment. The southern school, which became dominant, held to a doctrine of instantaneous enlightenment."

As Ch'an moved to become Zen in Japan, the remnants of this difference in Ch'an emphases maintained some relevance. The main branches transplanted froom China to Japan became Soto Zen (based upon the Northern-Ch'an influenced eachings of Dogen Zenji) and Rinzai Zen (based upon the Southern-Ch'an influenced teachings of Lin Chi. A third, but smaller branch in Japan was based upon the teachings of Obaku (Huang Po in Chinese). Huang Po, however was the teacher of Lin Chi and thus the differences between Obaku and Rinzai Zen are particularly nominal.

That said, it should be noted that the differences between Soto and Rinzai Zen are themselves mainly in procedure. Soto Zen adherents face a wall while meditating as did Bodhidharma while Rinzai adherents face into the room Both branches also practice walking meditation with Soto practitioners moving slowly around the room while Rinzai practitioner walk at a pace near normal.

Soto teachings emphasize "gradual enlightenment" while Rinzai accepts the possibility of "sudden enlightenment." The difference here is one of doctrinaire assumption. Soto simply believes that one reaches stages or states of enlightenment only through longer-term meditation while Rinzai accepts the possibility that recognitions or enlightenment may come "in a flash." Rinzai Zen also utilizes the contemplation of the koan as a tool for promulgating understanding while Soto does not.

In the United States and other western Zen, Soto, Rinzai and modern Ch'an techniques are utilized and modern references to "Northern" and "Southern" Ch'an differences focus mainly on techniques and style of ritual rather than any historical animosity that may have existed.

One can look at the Rinzai Lineage of Zen teachers and follow the further movement of Zen into Japan with the simple understanding that the teachings moved forward from there through both Rinzai via Eisai and Soto via the teachings of Dogen Zenji. Several other classical schools of Buddhism found limited following in Japan in the past. Obaku Zen is presently the third-largest of the Japanese sanghas, following Soto (1st) and Rinzai (2nd). Obaku Zen is also considered by many to be the "most Chinese" of the Japanese schools.

Although most Western Zen traditions identify themselves with the Soto school, "straight-up" Ch'an is also prevalent. Zen in the United States has recently seen the growth of other cultural varieties including the establishment of sizable Vietnamese, Korean Kwan Um and Son sanghas.