Now that it's 2020 and we into its third decade (or close enough for the sticklers), we're starting to see how the 21st century is shaping up.

But in its previous iterations, the '20s have been a massive time of change —from the economic spikes and seeds of war in the 1920s to the first pilgrims setting off to America in the 1520s

That means there are some big centenaries coming up that you might hear more about this year.

Let's take a look back at some of the defining moments.

1920

In 1920, the US passed the Nineteenth Amendment, enshrining the rights of women to vote. ( Wikimedia Commons: Ladies' Home Journal )

The hallmarks of the "Roaring Twenties" were (initially) economic growth and prosperity, as the wartime devastation of the previous decade gave way to social, artistic and cultural change.

At the turn of the decade, the national Country Party of Australia (now known as the National Party) was formed, while the Queensland and Northern Territory Aerial Service (which would later become Qantas) was founded in Winton, in Central West Queensland.

Across the pond, the United States passed the Nineteenth Amendment, enshrining the right of women to vote, while a nationwide ban on the production, important and sale of alcohol was imposed (and we all know how well that turned out).

Further abroad, Soviet Russia and the Democratic Republic of Georgia signed the Treaty of Moscow, recognising the latter's independence, while the Mexican Revolution came to an end when military leader Pancho Villa surrendered after reaching a peace agreement with interim Mexican President Adolfo de la Huerta.

Other notable moments in 1920 include:

Bloody Sunday (November 21, 1920): 32 people were killed in one of the most significant events to take place during the Irish War of Independence.

(November 21, 1920): 32 people were killed in one of the most significant events to take place during the Irish War of Independence. Wall Street bombing (September 16, 1920): 30 people were killed and hundreds more were injured following a bomb blast in the Financial District of Manhattan. The case has never been solved, although historians believe Italian anarchists may be responsible.

(September 16, 1920): 30 people were killed and hundreds more were injured following a bomb blast in the Financial District of Manhattan. The case has never been solved, although historians believe Italian anarchists may be responsible. George Polley, who earned the moniker "the human fly" for his uncanny ability to scale buildings, was arrested after climbing up the Woolworth Building in New York — which was, at the time, the world's tallest building.

Though George Polley was caught, Harry Gardiner (pictured), also known as the Human Fly, continued to operate. ( Wikimedia Commons: Evening public ledger )

1820

From scientific breakthroughs to new frontiers, the 1820s was truly a decade of exploration, discovery and change.

The year started with a shakeup for the British monarchy after 59 years with the death of George III, now the third-longest reigning monarch on January 20. His eldest son George IV (who had been Prince Regent during his father's decline) ascended to the throne.

The Essex, an American whaler and the real-life inspiration for Moby Dick, was attacked and sunk by a sperm whale in the southern Pacific Ocean in 1820, forcing its 20-man crew to fend for themselves.

The Essex, an American whaler and the real-life inspiration for Moby Dick, was attacked and sunk by a sperm whale in 1820. ( Wikimedia Commons: Nantucket Historical Association )

After reaching land, the men suffered severe dehydration and starvation — and reportedly resorted to eating each other. The remaining survivors were rescued some three months later.

Speaking of people with no limbs, the Venus de Milo, now one of the Louvre's star attractions, was discovered within the ancient city ruins of Milos during the same year (though it is believed to have been made by the sculptor Alexandros of Antioch in the 2nd century BC).

The Venus de Milo, now one of the Louvre's star attractions, was discovered within the ancient city ruins of Milos. ( Wikimedia Commons: Jimmy Wee )

British explorer Edward Bransfield claimed Trinity Peninsula, the northernmost part of the Antarctic Peninsula, for Britain.

Other notable moments in 1820 include:

Danish scientist Hans Christian Oersted became the first person to identify electromagnetism after watching a compass needle.

Danish scientist Hans Christian Oersted became the first person to identify after watching a compass needle. The Royal Astronomical Society , which would later honour the likes of Albert Einstein and Stephen Hawking, was founded in London.

The , which would later honour the likes of Albert Einstein and Stephen Hawking, was founded in London. Robert Gibbon Johnson, an American farmer and judge, reportedly proved that tomato was non-poisonous by biting into one on the steps of a courthouse in Salem, New Jersey (although there are various doubts around this claim).

1720

Calico Jack was captured and sentenced to death. ( Wikimedia Commons )

Ahoy, me Hearties! Or rather, goodbye, with 1720 marking the end of the "golden age" of piracy.

Infamous captain John Rackham, otherwise known as Calico Jack, and his two female crew members, Mary Read and Anne Bonny, were captured by pirate hunter Jonathan Barnet and swiftly sentenced to death in Jamaica.

Though he was ultimately hanged, Read and Bonny won stays of execution after claiming they were pregnant.

Elsewhere, England was hit with its own wave — the "South Sea Bubble".

The South Sea Company was founded to take over most of Britain's unconsolidated national debt, but it didn't quite go to plan. Share prices were massively inflated, before the English stock market crashed, creating a notorious economic bubble that ruined thousands of investors.

Other notable moments in 1720 include:

The Great Plague of Marseille reached French shores, killing a total of 100,000 people.

reached French shores, killing a total of 100,000 people. Edmond Halley, from whom Halley's Comet was named after, was appointed the second Astronomer Royal in Britain.

Edmond Halley, from whom Halley's Comet was named after, was appointed the in Britain. The Royal Cork Yacht Club, credited as the first yacht club in the world, was founded in Ireland.

1620

At the turn of the decade, the Mayflower set sail from England to what we now know as the United States, carrying more than 100 English Puritans — making this year its 400th anniversary.

Though bound for Virginia, stormy weather and navigational errors forced it off course, and the Pilgrims ultimately landed in Massachusetts, founding the first permanent European settlement.

Other notable moments in 1620 include:

Astronomer Johannes Kepler's mother was arrested for witchcraft and imprisoned for 14 months