The United Nations was born during the middle of World War II as the world seemed to be coming apart. Though its founding is officially celebrated in October, it was 72 years ago on Monday that 50 of the original member states signed the Charter of the United Nations after unanimously passing it the day before.

Since its founding, the organization has faced its share of criticism. Its agencies are credited with boosting health and education levels and helping to save millions of lives. But it has often been accused of being bloated and undemocratic, with just a few member states calling most of the shots.

President Franklin D. Roosevelt pushed for the creation of the U.N. during the deadliest war in human history as the key to preventing another massive global conflict. It was Dag Hammarskjöld, the second U.N. secretary general, who said the entity “was created not to lead mankind to heaven but to save humanity from hell.”

The U.N. Charter gave the organization the authority to maintain international security, establish democracies and promote peace. Here’s a look at five of its biggest aid agencies.

UNICEF

The United Nations Children’s Fund defends the rights of children and seeks to improve their standards of living around the globe. Since 2010, UNICEF programs have helped save the lives of 48 million children by providing nutritional assistance, vaccines and clean water. Today, the agency also promotes education and gender equality, protects children from abuse and exploitation and partners with governments to ensure child well-being. The organization, one of the U.N.’s most recognizable, responded to 344 humanitarian emergencies in 108 countries in 2016 alone.

World Health Organization

The World Health Organization works with governments and organizations in more than 150 countries to promote international public health and combat preventable death and disease. During the past 10 years, health and life expectancy have improved in nearly every country and deaths from malaria and HIV have declined by half. The number of child deaths dropped by half between 2000 and 2015 as a result of WHO intervention — 19,000 fewer deaths each day. Since the turn of the millennium, the agency’s efforts to stop tuberculosis have saved nearly 50 million lives. The agency established the Health Emergencies Programme after the 2014 Ebola virus outbreak in West Africa, allowing WHO to respond faster and more effectively to health emergencies. WHO plans to expand access to medicine, health care coverage and potable water.

UNHCR

The U.N.’s refugee agency provides aid and defends the rights of tens of millions of refugees, internally displaced people and other forced migrants, with 470 locations in 128 countries. In 2016, 67.7 million people remained a concern for UNHCR, a 3.8 million increase from 2015. Countries receiving a bulk of assistance include Syria — where 11.5 million people are refugees or internally displaced — Iraq, South Sudan, Burundi, Myanmar and Yemen. In 2016, 25 countries made legislative changes that increased the protections of refugees and asylum-seekers, and nearly 61,000 stateless people gained a nationality or had their own confirmed.

World Bank

The World Bank provides financial and technical support for developing countries, with more than 120 offices around the world. It partners with local governments and organizations to provide loans, credits and grants for investments in education, health, infrastructure, business development, agriculture and public administration. Since 2000, more than 1 billion people have been lifted from poverty, and in 2015 the World Bank estimated that the percentage of people living in extreme poverty — those surviving on less than $1.90 a day — around the globe fell below 10 percent for the first time. By 2030, the organization plans to lower that figure to about 3 percent, as well as assist in income growth for the bottom 40 percent of every country.

UNESCO

The United Nations Educational, Scientific and Cultural Organization prioritizes sustainable development, freedom of expression and education through its initiatives in China, Costa Rica and dozens of other countries. The agency works mainly to promote equality and raise awareness of challenges facing indigenous people, the disabled, women, children and disadvantaged groups. In 2015, UNESCO hosted a World Press Freedom Day conference to highlight the importance of a fair, open and safe news media. It recognized the more than 700 journalists have been killed during the past decade. UNESCO also protects its World Heritage Sites that are deemed culturally and historically significant from decay and cultural cleansing. Egypt’s pyramids, Australia’s Great Barrier Reef and the United States’ Grand Canyon are among the 1,052 listed properties.

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5 United Nations Agencies You Need to Know originally appeared on usnews.com