The Book of Lismore, containing the written record of the story of "The Siege of Knocklong", was composed around 1480.
It was discovered hidden in the walls of Lismore Castle, Co. Waterford in 1814.

Approximately in the year 250 ADE, midway through his reign as High King of Ireland, Cormac Mac Airt led his army into Munster to collect extra taxes and tributes. Fiacha Moilleathan, King of Munster, and the Munstermen resist Cormac's claims and defeat Cormac and his Northern army at Knocklong.
Cormac was warned by his Druids that his claims were unjust and that his army would be slaughtered. He ignored all advice.

The Siege of Knocklong describes the journey of Cormac and his army southwards. They travel 5 days and 5 nights, arriving on the Hill of Knocklong on the sixth morning of travel. They lose a week enroute due to Druid mischief.

Cormac sets up his camp at Droim Dámhgháire (Knocklong) and Fiacha sets up at Ceann Chláire (Glenbrohane).

The siege lasts over a year and includes five battles between the opposing armies. When the battles fail to bring the Munstermen to submission, Cormac's druids dry up all sources of water in the area, and the siege begins.
This act nearly drove the Munstermen to death. Fiacha turned to the powerful Munster druid Mug Ruith for aid. He restored the water supply. The Munstermen regain their strength and with Mogh Ruith's help, they defeat Cormac and drive his army out of Munster.

The Decision to invade Munster

The Druids

The Journey from the Hill of Tara to the Hill of Knocklong

The Battles at the Ford

The Siege Begins. The lakes and rivers are dried up

Return Journey to Sliabh Fuait