Sinforiano García Sanz was born in Robledillo de Mohernando on June 8, 1911, where he was educated in the old way, between his family and his teacher. At the age of 11, he finished the primary education that he could receive in his town and went to Madrid.

In Madrid, he performs different jobs as a cloth-cutting waiter until he becomes a helper's guild. He worked at the Center for Historical Studies, today the Higher Council for Scientific Research. Here he met and collaborated with various personalities from the world of culture, such as Francisco Layna Serrano, Tomás Camarillo, José Antonio Ochaita, José Sanz y Díaz, Claro Abánades, Castillo de Lucas, José María Alonso Gamo, Ramón de Garciasol...

In 1949 he set up a small bookstore on Calle Fuencarral in Madrid.

He was a founding member of the Casa de Guadalajara in Madrid, holding various positions, including librarian.

In his travels and meetings with the people of the towns, which in the 40s were still very isolated, he discovered those festivals that no one had ever talked about: the botargas and the masked alcarreños. Even getting to the attention of who at the time was the most knowledgeable in folklore in Spain, Julio Caro Baroja.

Regular collaborator in the Alcarreño press of the moment: Nueva Alcarria and Flores y Abejas. Little by little he specialized in the description of customs, festivals, rites, songs. Although its bibliographical production is not abundant, it is nonetheless a great reference, as is evident in several specialized magazines, including the Revista de Dialectología y Tradiciones Populares or the Cuadernos de Etnología de Guadalajara.

Sinforiano died in Madrid on June 23, 1995.

The essence of Sinforiano's work is very well collected and expressed by the Provincial Chronicler of Guadalajara, Antonio Herrera Casado in his memory of Sinforiano in June 2011, who says: "From his writings I learned the respect with which one has to approach the popular demonstrations at parties and celebrations. He was the first to point out the interest of a party that until then had gone unnoticed among classical historians.

In the 80s of the last century, the Provincial Council of Guadalajara acquired García Sanz's personal library, becoming one of the most important collections for scholars of ethnology and folklore, which is kept in the Library of Investigators of the Guadalajara Province.