COVID-19 is just the latest in a long line of pandemics that have devastated societies. We revisit the greatest pandemics of human history.

Like all pandemics, COVID-19 was sparked by human interaction with the animal world. We look at the circumstances that have caused these diseases - whether it be hygiene, poverty, overcrowding, urbanisation or the growth of cities - and how travel has impacted on their rapid transmission - resulting in pandemics. We explore the symptoms of these diseases and their impact - whether it was the Black Death - Bubonic Plague - which cost 100 million lives in 14th century Europe, or the Smallpox pandemic transmitted by Europeans which wiped out indigenous communities in the Americas, Pacific and Australia between the 15th and 18th centuries. The Great Plague of the 17th century and the Spanish Flu outbreak at the end of World War I, were equally devastating in Europe. Quarantine measures were first widely introduced and debated 700 years ago and now in the 21st Century with COVID-19, their effectiveness is being debated again. Science, which searched for and found cures and vaccines to old diseases is once again on a quest for a new one as the world seeks solutions to a crisis that threatens its very way of life.