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Of all the battles in the fight against ISIS, the operation to retake Mosul could prove the most significant.

Two and a half years since 219 Chibok schoolgirls were abducted by Boko Haram in Nigeria, sparking a global outcry and the #BringBackOurGirls campaign, there has finally been some good news. Yesterday, 21 of those girls were reunited with their families in an emotional ceremony in Abuja, embracing the parents they thought they'd never see again.

So it begins: The long-envisioned assault on Mosul, the hugely symbolic Iraqi city where Abu Bakr al-Baghdadi declared ISIS' self-styled "caliphate" more than two years ago.

A major offensive to recapture Mosul from ISIS is under way, as Iraqi-led forces advance on the city, which has been under the terror group's control since June 2014.

The world's oldest panda in captivity died Sunday in Hong Kong's Ocean Park.

Pepsi says it's getting serious about cutting sugar from its drinks.

ISIS got smacked with a trio of setbacks over the weekend, with the loss of a key city, the death of an influential figure and -- oh yes -- the invasion of its biggest stronghold in Iraq.

The assault on Mosul has begun after months of planning and often tortuous negotiation about the make-up of the attack force.

It was tears of joy for a seven-year-old boy from Queensland, Australia, whose hard-won savings finally earned him biggest wish.

Fourteen unaccompanied refugee teenagers from the notorious "Jungle" migrant camp in Calais, France, have arrived in Britain.

Iran has some tough new competition in the race to capitalize on India's booming demand for oil.

Ever had a tube journey from hell? How about a tube journey into hell -- or out of it, depending on which way you're traveling.

Cai Guo-Qiang is back, and with his most ambitious project to date: a 1,650-foot ladder in the sky made of -- what else? -- fire.

The 21 Chibok schoolgirls kidnapped and released by terrorist group Boko Haram were reunited with their families amid tearful scenes on Sunday.

As the assault to liberate the Iraqi city of Mosul from ISIS begins, Clarissa Ward explains why the city is so important.

As Thailand mourns the loss of King Bhumibol Adulyadej, who reigned for more than 70 years, visitors to the country may be wondering what impact the situation will have on their journeys and how they can show their respect.

Of the roughly 197 Chibok schoolgirls who still are unaccounted for after Islamist militants kidnapped them in Nigeria two years ago, only 83 will be negotiated for when the West African nation's government resumes talks for their release, two sources with direct knowledge of the negotiations said.

On Christmas Eve in 1968, Apollo 8 made the first manned mission to the moon. Live broadcasting from the spacecraft was the three-man crew of Frank Borman, Jim Lovell and William Anders, and it was on that day that their journey led them to an unexpected sight.

As ISIS awaits one major assault in Mosul, Iraq, the self-declared caliphate has lost its control of a symbolic stronghold in north Syria.

A long-awaited operation to seize the key Iraqi city of Mosul after two years of ISIS control will begin in the coming days, militia groups warned Sunday after Iraqi forces told people not to panic and to seal their doors and windows.