Eihei Dogen, the founder of Soto Zen in Japan, was a prominent Zen master and philosopher during the 13th century. His teachings had a profound impact on the development and spread of Zen Buddhism, not only in Japan but also beyond its borders.

One of the key factors that contributed to the spread of Dogen's teachings was his emphasis on the importance of direct experience and practice over mere intellectual understanding. This approach resonated with many people, both in Japan and abroad, who were seeking a more experiential and practical form of spirituality.

Another significant factor was Dogen's emphasis on the concept of "zazen," or seated meditation, as the primary practice of Soto Zen. This practice, which involves sitting in a specific posture and focusing on the breath, was accessible to people of all backgrounds and did not require any prior knowledge or belief system. As a result, it appealed to a wide range of individuals, including those from different cultures and religions.

Dogen's teachings also gained popularity through the efforts of his disciples and successors, who spread his teachings through their own teachings and writings. One of his most influential disciples, Keizan Jokin, established the first Soto Zen monastery in Kyoto in the 14th century, which became a center for the dissemination of Dogen's teachings.

In addition to the efforts of his disciples, Dogen's teachings also spread through the translation of his writings into other languages. In the 20th century, Dogen's works were translated into English and other Western languages, making his teachings accessible to a wider audience.

Furthermore, Dogen's teachings gained recognition and respect from other Buddhist schools and traditions, both in Japan and abroad. His emphasis on the unity of practice and enlightenment, as well as his rejection of dualistic thinking, resonated with the teachings of other Buddhist schools and helped to bridge the gap between different traditions.

Today, Dogen's teachings continue to spread through various means, including meditation centers, retreats, and online resources. His teachings have also influenced other fields, such as psychology and philosophy, and continue to inspire individuals from all walks of life to seek inner peace and enlightenment.

In conclusion, Eihei Dogen's teachings spread beyond Japan through various factors, including his emphasis on direct experience and practice, the efforts of his disciples, the translation of his writings, and the recognition and respect of other Buddhist schools. His teachings continue to have a profound impact on individuals and communities throughout the world, making him one of the most influential figures in the history of Zen Buddhism.