Today, Sunday, August 19, thousands of Afghans around the country will celebrate the 99th anniversary of Independence Day.

Official ceremonies will take place in various parts of the country and thousands of families and friends will spend the day together to mark the event. 

In addition, a new flag, the biggest in the country, will be hoisted on Wazir Akbar Khan hill in Kabul.  

Over the past few days, banners and flags have been erected throughout the city while in Jalalabad the town’s center was draped in neon lights – which brought cheer to thousands of residents in the war-weary city. 

Security is however expected to be tight in cities, particularly in Kabul – where the official ceremony will be held. 

This national holiday honors Shah Amanullah Khan's defeat of the British Empire in 1919 and the founding of the nation.

In the lead up to Independence Day, dozens of flag sellers have been walking the streets of Kabul and other cities, selling their wares.

Although Afghanistan was never part of the British Empire, it gained its independence from Britain after the signing of the Anglo-Afghan Treaty in 1919 – a treaty that granted complete neutral relations between Afghanistan and Britain.

And although not having been part of the British Empire, Britain fought three wars in the country.

The first Anglo-Afghan War (1839-1842) led to the defeat of the entire British-led Indian invaders by Afghan forces under Abdur Akbar Khan. The second Anglo-Afghan War (1878-1880) first saw the British defeated in the Battle of Kandahar only for them to emerge victors – which led to Abdur Rahman Khan becoming the new emir.

This ushered in a new era of friendly British-Afghan relations. Following this war, the British were given control of Afghanistan's foreign affairs in exchange for protection against the Russians and Persians.

In 1901 Abdur Rahman Khan's son, Habibullah, succeeded him.

Habibullah was a relatively reform-minded ruler who attempted to modernize his country. During his reign he worked to bring modern medicine and other technology to Afghanistan and worked to put in place progressive reforms in his country.

He was assassinated while on a hunting trip in Laghman Province on February 20, 1919. His brother Nasrullah Khan briefly succeeded him as emir and held power for a week before being ousted and imprisoned by Amanullah Khan, Habibullah's third son.

However, the third Anglo-Afghan War started the same year and resulted in the British giving up control of Afghanistan's foreign affairs in 1921.

Within a few months, the new emir had gained the allegiance of most tribal leaders and established control over the cities.

Amanullah's ten years of reign initiated a period of dramatic change in Afghanistan in both foreign and domestic politics. Starting in May 1919 when he won complete independence in the month-long Third Anglo-Afghan War with Britain, Amanullah altered foreign policy in his new relations with external powers and transformed domestic politics with his social, political, and economic reforms.

Although his reign ended abruptly, he achieved some notable successes.

Before final negotiations were concluded in 1921 on the foreign policy issue, however, Afghanistan had already begun to establish its own foreign policy, including diplomatic relations with the new government in the Soviet Union in 1919.

During the 1920s, Afghanistan established diplomatic relations with most major countries, and Amanullah officially became king in 1923.

On 14 January 1929, Amanullah abdicated and fled to neighboring British India while Afghanistan fell into a civil war. From British India he went to Europe where he died in Zürich, Switzerland, in 1960.