In 1929, Dr. Montessori sought to formalize control her work under a single organization, led by her son and heir, Mario. Through this organization, named “Association Montessori International” (AMI), Mario consolidated control of all his mother’s educational activity, including certification of teachers, copyright control of her published writings, and coordination of activities conducted by various affiliated national and regional “Montessori” organizations that emerged.
After Dr. Montessori’s death in 1952, Mario continued to control the operation of AMI; however, now without the personal power and authority of Dr. Montessori herself.  As Mario came into conflict with others who disputed his exclusive claim to authority in the field, divisions arose in the Montessori community, leading to the formation of new, non-AMI organizations, which owed no personal loyalty to Mario. When Mario died in 1982, AMI continued under control of the heirs and family members of Mario Montessori, and later through those who were most closely associated with Mario during the time of his leadership.
Today, AMI continues as a self-defined official authority for Montessori education, representing a type of “personality” philosophy in the field since it is so closely defined by its personal relationship with Dr. Montessori herself.