Master Hui-Neng
The Sixth Patriarch, (638 - 713)

In the history of Zen, three or four people are so important, there would be no Zen today without them. Hui Neng (Eno, in Japanese) is one of those people. In spite of being a poor, illiterate, social outcast he became 6th patriarch of Zen School, showing the accepting nature of Buddhism. He is the only Chinese whose words are considered to be a "sutra" (his autobiography and Zen commentary were recorded and formatted into the Platform Sutra, one of the most important texts in Zen Buddhism.
Hui Neng was living in the bad part of Canton when he heard a monk reciting the Diamond Cutting Sutra. On hearing this, he was immediately enlightened. He arranged financial support for his mother, who he was caring for, and left to see the Fifth Patriarch and join his temple as a monk.
The head monk accepted him, but knowing Hui Neng's humble origins would see him disrespected by unenlightened junior monks, he gave him low level work in the kitchen.
One day the Patriarch announced he would choose the next Patriarch by means of a competition. Monks could write a poem about developing Prajna (wisdom) to show their depth of understanding.
The most senior monk wrote the following poem on the wall.

Our body is the Bodhi-tree,
And our mind a mirror bright.
Carefully we wipe them hour by hour,
And let no dust alight.
The Patriarch told him: "Your stanza, shows that you have not yet realized the Essence of Mind. So far you have reached the 'door of enlightenment', but you have not yet entered it. To seek for supreme enlightenment with such an understanding as yours can hardly be successful.

Next Huineng got a junior monk to write poetic reply on the wall for him since he was illiterate.

There is no Bodhi-tree,
Nor stand of a mirror bright.
Since all is Void,
Where can the dust alight?

The Patriarch was delighted. He gave Huineng some final instruction including this poem:

Sentient beings who sow the seeds of enlightenment
In the field of causation will reap the fruit of Buddhahood.
Inanimate objects void of Buddha-nature
Sow not and reap not.

Huineng left immediately spending many years anonymously on the road until one day he visited the Guangxiao Temple in Canton. Two monks were debating. One said the temple flag was moving; the other said the wind was moving. Huineng's famous comment was that it was actually third minds that wee moving.
The Head monk knew from the speed and depth of the visitor's comment, that this must be the famous Huineng. From here on the Master came out of his retreat and greatly empowered Zen through his creation of the Nanhua Monastery, his lectures, guidance and especially his creation of the Platform Sutra. This is the only Chinese text given Sutra status, meaning it is of equal value with the words of the Buddha.

The Sutra is good reading, but you'll need a good teacher to explain it. It would be easy to spend an hour explaining a single sentence, such as: "Merits will be of no help if your Essence of Mind is obscured."
Huineng was at the middle of a debate about Sudden and Gradual Enlightenment. He advocated his Sudden Enlightenment path if the students were ready to follow it. Others in the north, thought enlightenment would come gradually through effort and practicing good behaviour. The Northern, Gradual School died out and all modern schools of Zen are from Huineng's Sudden school.