National Day in Qatar, also known as Founder's Day, is celebrated on December 18.
This public holiday marks the day Jassim bin Mohammed Al Thani took power as emir of the Qatari Peninsula.
This day is considered to be the day of the inception of the modern State of Qatar.
Sheikh Jassim bin Mohammed Al Thani became the emir of the Qatari Peninsula on December 18, 1878, following the death of his father Mohammed bin Thani.
He unified all the local tribes and earned autonomy for the Qatari Peninsula, which was recognized by both the Ottoman Empire and the United Kingdom.
Sheikh Jassim is considered to be the founder of modern Qatar.
Originally National Day of Qatar was celebrated on September 3, the anniversary of the country's independence from the UK.
In 2007 its date was changed to December 18 to commemorate the country's unification and the founding of modern Qatar.