Fireworks explode around the London Eye during New Year's celebrations in central London just after midnight on January 1, 2019. (AFP/Adrian Dennis)
Revelers welcomed 2019 with fireworks displays and festivities as a celebratory wave swept westward across the globe from Asia to Europe and the Americas at the conclusion of a tumultuous year.
Monday's celebrations kicked off with Sydney hosting its biggest-ever pyrotechnics display and lighting up its harbor-front skyline for a full 12 minutes.
More than 1.5 million spectators gathered to enjoy the spectacle that also featured a ceremony to celebrate Australia's indigenous culture.
In Hong Kong, hundreds of thousands of party-goers packed the streets on either side of Victoria Harbour for a spectacular 10-minute show that burnt through $1.8 million worth of fireworks.
In the Indonesian capital Jakarta, more than 500 couples tied the knot in a free, mass wedding organised by the government to mark the arrival of a new year.
Fireworks shows, however, were cancelled out of respect for victims of a December 22 tsunami that killed more than 400 people.
In Japan, locals flocked to temples to ring in 2019, as US boxing superstar Floyd Mayweather came out of retirement to beat Japanese kickboxer Tenshin Nasukawa in a multi-million-dollar "exhibition" bout outside Tokyo.
In Dubai, fireworks lit up the sky over the world's tallest building, the Burj Khalifa, to the delight of onlookers, while nearby Ras al-Khaima sought to enter the Guinness Book of Records with the world's longest fireworks show.
Russia saw in the new year progressively over several time zones starting in the far east, with concerts and light shows planned for Moscow city parks, and more than 1,000 ice rinks opened for merrymakers.
But a tower block gas explosion that killed at least four people and left dozens missing cast a shadow over New Year's celebrations.
In his New Year's address to the nation, President Vladimir Putin urged people to work together to "increase well-being and quality of life so that all citizens of Russia... feel changes for the better in the coming year."
In Paris, fireworks and a light show with the theme "fraternity" were scheduled for the Champs-Elysees despite persistent "yellow vest" anti-government protests.
French President Emmanuel Macron, in a televised address, acknowledged the French government "can do better" by citizens complaining of shrinking spending power.
In Berlin, music lovers partied at a concert at the Brandenburg Gate, while Britain's capital London opted to usher in the new year by celebrating its relationship with Europe, despite Britain's impending departure from the European Union.
London's fireworks display would seek to show Europe that the British capital would remain "open-minded" and "outward-looking" post-Brexit, said the city's mayor Sadiq Khan.
In Portugal, dozens of people, some in costume, will brave the winter for a traditional New Year's ocean dip near Lisbon, while in the Democratic Republic of Congo, election officials will be counting votes after a presidential election Sunday.
In Nigeria, President Muhammadu Buhari used his New Year's address to promise a free and fair election in 2019, while Ivory Coast leader Alassane Ouattara vowed the creation of a new, independent, electoral commission for polls planned for 2020.
When the celebrations reach the Americas, Rio de Janeiro's famous hilltop Christ the Redeemer statue will be brought to 3D life with special light projections before fireworks illuminate the city's Copacabana beach where around two million people are expected to party till dawn.
As the world celebrates, many are wondering whether the turmoil witnessed in 2018 will spill over into the next.
The political wrangling in Westminster over Brexit was one of the key stories of this year, with a resolution yet to be reached ahead of Britain's scheduled March 29 departure.
US President Donald Trump dominated headlines in 2018, ramping up a trade war with China, quitting the Iran nuclear deal, moved the US embassy to Jerusalem, and meeting his North Korean counterpart Kim Jong Un.
North Korea's commitment to denuclearisation will remain a major political and security issue into next year, as will Syrian President Bashar al-Assad's reassertion of control after Trump's shock announcement of a US troop withdrawal from the country.
The war in Yemen, which has killed about 10,000 people since 2014 and some 20 million at risk of starvation, could take a crucial turn in 2019 after a ceasefire went into effect in mid-December.
Numerous countries go to the polls in the coming year, including India, Afghanistan, Indonesia, Nigeria, South Africa, Argentina, and Australia.
Major sporting events on the calendar include the Rugby World Cup in Japan, the cricket one-day international World Cup in England, and the athletics World Championships in Qatar.