Flags are being flown across Wales to celebrate 600 years since Owain Glyndŵr held his first Welsh Parliament.
Glyndwr led a successful military campaign against the English
The rebel leader was crowned as Prince of Wales at Machynlleth in 1404.
He is considered one of the great heroes of Welsh history.
Events have been taking place in Machynlleth since May to mark the anniversary
To note Glyndŵr day on 16 September people throughout Wales will be celebrating by flying his flag and participating in activities.
In Nant Gwrtheyrn, a language and heritage centre on the Llyn Peninsula has been staging a week-long event for local primary schools.
Pupils have been learning about Glyndŵr's uprising through storytelling, role-playing and poetry .
"This week of events has proved most popular once again," said Elen Thomas, Nant Gwrtheyrn's Education Officer.
"All the days were booked up almost immediately after we advertised them and unfortunately we've had to turn away some schools."
In the early 15th Century the Welsh were fired by anti-English feeling after much of the country had been subjected to centuries of their rule, and Glyndŵr mobilised this national sentiment.
Backed by French military aid, Glyndŵr took Carmarthen and Cardiff in 1403 from the English and Harlech and Aberystwyth in 1404.
However the tide turned against the Welsh as England's superior resources and weaponry were turned on them under the leadership of the future Henry V.
By 1409, the revolt was broken and the many towns and castles Glyndwr had taken were lost. He was forced to turn to guerrilla warfare until his obscure death in 1416.
Aberystwyth Town Council is celebrating Glyndŵr's day by flying his standard on the town council's flagpoles.
Embassy Glyndŵr, a society which promotes Glyndŵr's history, is campaigning for 16 September to be declared a national holiday.