The National Day of Qatar is on the 18 December (Official National Day; the assumption of power of Sheikh Jassem bin Mohamed al-Thani in 1878).
Founder’s day celebrates the rise to power of Sheikh Jassem bin Mohamed bin Thani. Jassem is usually regarded as the father of the state of Qatar. Although Jassem’s father, the headman of Doha, was originally recognised as the head of the leading family in Qatar, at the time Qatar consisted of many different tribes and could not send to be a cohesive nation.
When Jassim took over he consolidated the family’s power. However, it was his victory over the Turks that made him into a national hero, and is considered by some as the foundations of the modern Qatar state.