It is home to an estimated 11 million people in eastern China.

It is here where health officials believe the new coronavirus originated and eventually spread across the globe.

Cases of the disease it causes, known as COVID-19, have risen rapidly as health officials have worked to contain the virus.

Here's how COVID-19 became a global pandemic.

On December 1st, 2019, a patient in Wuhan begins to show symptoms of viral pneumonia, according to a report in the Lancet medical journal.

That patient is believed to be the first documented case of the virus.

Throughout the month, a series of pneumonia cases of unknown cause emerge in Wuhan.

Symptoms include a fever, labored breathing and a dry cough.

At the end of the month, the Chinese government informs the World Health Organization of a cluster of pneumonia cases in Wuhan.

Between December 31st and January 3rd, a total of 44 cases are reported to the WHO.

Many of the patients were found to have visited an open-air seafood and animal market within the city.

Chinese authorities shut down the market, and on January 5th, the WHO reports the infection could be connected to exposure to live animals.

Chinese scientists discover sick patients are infected with a new strain of coronavirus, according to Chinese state media.

Coronaviruses are a large family of viruses that include the common cold.

At this point, there are no documented instances of human to human transmission.

On January 11th, China reports the first death from the disease in Wuhan.

Concerns grow about the ability to contain the virus over the upcoming Chinese lunar new year, when millions of people travel across the country.

Wuhan is connected to other major Chinese cities by nearly 22,000 miles of high speed rail, and connected to the world via an international airport that transports 24.5 million passengers a year, and connects to 30 cities around the globe.

A Chinese tourist traveling from the Wuhan area is found to have a fever after arriving at the airport in Bangkok, Thailand.

On January 13th, this person is confirmed to have the first case of the new coronavirus outside of mainland China.

Over the next week, cases appear across Asia, and in the United States as well.

According to the WHO, on January 23rd, there are 581 confirmed cases globally.

As health officials announce the virus can spread between humans, the Chinese government cuts train and air travel out of Wuhan, effectively quarantining the entire city in an effort to contain the spread.

With over 7,800 confirmed cases, the WHO declares the coronavirus a global public health emergency, indicating authorities believe the virus is a significant threat beyond China.

In Yokohama, Japan, passengers aboard the Diamond Princess cruise liner are quarantined.

For almost three weeks, passengers are confined to the ship as they are tested for the virus.

696 people on the ship are ultimately confirmed to be infected, including some Americans.

A week later, the WHO officially names the disease COVID-19.

The name is an abbreviated form of coronavirus disease 2019.

On February 17th, the number of new cases reported by the WHO rises sharply, after Chinese authorities change the criteria for diagnosing the illness, raising concerns that the virus is speeding up, not slowing down.

Up until this point, the vast majority of cases have been confined to mainland China, but by February 24th, new cases flare in South Korea, Italy and Iran.

In the United States, thousands of people are asked to self-quarantine to curtail infections in several states.

State health officials in California, Oregon and Washington report new cases of COVID-19 with no travel history to China or known exposure to carriers.

Worries increase that the virus is spreading in American communities.

The number of confirmed coronavirus cases globally tops 100,000, as President Trump signs into law an 8.3 billion USD spending bill to combat the virus.

Over the next week and a half, major sporting events are canceled, schools and businesses are closed, and many Americans are advised to stay home to limit contact with others.

On March 13th, the president declares a national emergency, as the virus continues to create major disruptions to American life.

COVID-19 continues to spread and impact communities around the globe, as health officials monitor the disease, and try to find ways to curtail it.