Eihei Dogen, also known as Dogen Zenji, was a Japanese Buddhist monk and the founder of the Soto Zen school of Buddhism in Japan. He was born in 1200 in the province of Kaga, in what is now known as Ishikawa Prefecture, Japan.

Dogen was born into a noble family, with his father being a high-ranking official in the government. However, at a young age, Dogen became interested in Buddhism and decided to pursue a monastic life. He left his family and traveled to the capital city of Kyoto to study Buddhism under the guidance of various masters.

After several years of studying and practicing, Dogen became dissatisfied with the state of Buddhism in Japan. He believed that many monks were more concerned with ritual and ceremony rather than the true essence of Buddhism. This led him to travel to China in 1223, at the age of 23, to deepen his understanding of the teachings of Zen Buddhism.

In China, Dogen studied under the guidance of the renowned Zen master Rujing. He spent four years studying with Rujing and eventually received Dharma transmission, making him a fully ordained Zen master. During his time in China, Dogen also studied the teachings of the influential Zen master Hongzhi Zhengjue.

In 1227, Dogen returned to Japan with a new understanding of Zen Buddhism and a mission to spread its teachings. He faced many challenges and criticisms from other Buddhist schools, but he remained steadfast in his beliefs and teachings.

Dogen eventually settled in the mountains of Echizen, where he established his own monastery, Eiheiji. He also wrote many influential works, including the "Shobogenzo," a collection of his teachings and insights on Zen Buddhism.

Today, Dogen is considered one of the most important and influential figures in Japanese Buddhism. His teachings and writings have had a significant impact on the development of Soto Zen and continue to be studied and practiced by Zen practitioners around the world.

In conclusion, Eihei Dogen was born in the province of Kaga, Japan, and spent his early years studying and practicing Buddhism in Kyoto. He later traveled to China, where he studied under the guidance of renowned Zen masters and eventually returned to Japan to establish his own monastery and spread the teachings of Zen Buddhism.