There are four fairly distinct periods in freediving history, mostly divided by new advances in equipment. Naturally there are some grey areas in between the ages, and certainly the dates differed from place to place.
More information needed, feel free to contribute.
From the earliest times to just before the invention of the fin. Goggles are virtually unknown outside Japan. Some early cultures made lenses out of polished turtle shells and used palm leaves and tar for fins. Most spearfishing is done from the surface.
1800s - Japanese Ama divers begin two centuries of freediving.
1913 - Stotti Georghios retrieves an anchor in 200 feet (61 m) of water.
The invention of the fin and the use of goggles starts to become widespread. Early European "gogglers" and "sinkers" explore the Mediterranean (Hans Haas, Jacques Cousteau, and Guy Gilpatrick). Freediving/spearfishing clubs organize in California.
1933 - Louis M. DeCorlieu patents "Lifesaving and Swimming Propelling Device", aka fins.
1933 - The San Diego Bottoms Scratchers forms (Glen Orr, Jack Prodonovich and Wally Potts among others).
1938 - Guy Gilpatrick publishes The Compleat Goggler.
1943 - Jacques Cousteau and Emile Gagnan invent SCUBA gear.
1949 - National Geographic estimates that there are roughly 8000 freedivers in the United States.
The mask, fins and snorkel develop into a mature state, resembling modern SCUBA equipment.
1950 - Cressi manufactures a mask that encloses the nose and provides finger pockets, allowing the mask to be equalized as well as the ears.
1950 - The International Underwater Spearfishing Association forms.
1951 - Skin Diver Magazine begins publishing.
1953 - Neoprene wetsuits become commercially available.
Long blade fins appear. Further advances in technology are evolutionary including carbon fibre fins and advanced neoprene wetsuits. Bluewater hunting gear (Tuna guns, sophisticated terminal gear) is available commercially.
1970 - The first long-bladed freediving fins appear.
1999 - The RetroSub Freedivers form.