While many historical articles and chapters on the foundations of Instructional Design and Technology (IDT) have painted an accurate picture of the field, it has been 21 years since anyone has given emphasis to the relationships of influence among IDT scholars. Many have written on various elements of the field, emphasizing events according to their own experience, which have increased our overall understanding of IDT. However, without insight on the connections between these pieces, the field appears to be only a broad array of isolated silos, each filled with its own research interest. This research sought to discover IDT's genealogy of influence. Three main research questions were asked: "Currently, who are the most influential scholars in IDT?" "Who influenced today's most influential scholars?" and "What ideas were most influential in the scholars' relationships?" The ten most influential names in IDT were discovered, and their genealogies of influence were traced. The ideas that were most influential in the relationships between theorists were summarized into the following groups of fields: General Education, IDT (and its contributors), Psychology, Sociology and Anthropology, and Adult and Higher Education. This research found an IDT field that was very diverse but very connected. Another important result was much less expected: the prevalence of psychology as a significant influence on both past work and current big ideas. Implications are discussed, such as revising definitions of the field.