Watch how the bikini has changed over the past 120 years

As you can see, women's beachwear was fairly modest for the first few decades, with the '30s seeing the introduction of something resembling a modern-day swimsuit.
Viner, Amanda Cerny, does a great job of modelling the outfits and shows how the sexually liberated '60s brought the jump to what we would recognise as a bikini today, before the '80s introduced a more risqué version.