William D. S. Daniel was born on March 17, 1903 in Urmia, Iran. He completed his primary education in the missionary schools where he studied the Assyrian language. After the First World War, William moved to Hamadan and began studying music. He later went to study in the conservatory of music in Basil, Switzerland where he became an accomplished violinist. While in Europe, he continued to study the Assyrian language and took to translating the French masterpiece "Cyrano de Bergerac" from French to Assyrian.
William returned to Iran in 1937, and after a few years settled in Tehran and turned his attention to composing original Assyrian music. In 1943, William wrote songs for the weekly Assyrian program broadcast on national radio. Moreover, William organized a choir, numerous plays and concerts, and taught classes in the Assyrian language and literature.
In Tehran he also began working on his lifelong ambition, writing the Assyrian Epic of "Kateeny the Great" in verse. He completed the first volume of the epic and also wrote an Assyrian book of verse for children titled "Rameena the Naughty". Both books were published in 1961 by the Assyrian Youth and Cultural Society of Tehran. William's first book of songs, "The Rays of Light" was also published at this time.
William immigrated to the United States in 1952 and settled in Chicago. There he continued to teach the Assyrian language, wrote music, organized plays and choirs, wrote articles for the Assyrian magazines and gave lectures at various functions. He was the editor of the periodical "Mhadyana" in the 1960's. In 1970, his musical piece, "Juvenile Suite", won the Beblis award. William published the second volume of "Kateeny the Great", his music collection "William Daniel's Creations", "Assyrians of Today, Their Problems and a Solution", and the bilingual play "Kismat" in Chicago.
In 1979, William came to San Jose, California. During his years in San Jose, William served as the Editor of the Assyrian Star magazine, wrote numerous articles, poems, and musical pieces. In 1983, he published the third and last volume of the epic of "Kateeny the Great", immortalizing it in a compilation of over 7,000 verses, and narrated Volume I and II of the Epic on tape.
In 1992, his students in San Jose honored him posthumously by collecting his previously unpublished poems in Assyrian and English in an illustrated, full color book titled "Tapestry", published by the Assyrian American Association. San Jose is the eternal resting place of this prominent Assyrian personality.