Italy and France were the major source of simulators early in the 18th century. These were made of fabric and mostly for obstetrics - ie training midwives. Training was to reduce risk to the patient, as it is today.
much broader applications became apparent
Simulating with mannikins grew in popularity as did the percieved benefits in education programs. Patient safety and better practical learning - the benefits were obvious.
The exponential growth in technology and modern manufacturing has brought medical simulation into a new era. The gap between learning on a live patient and a medical simulator has become much smaller. The reason why - effective training and patient safety - is still the same as it was 300 years ago.