Kalends of January first feria, thirteenth of the moon, AD 1021.
A defeat was inflicted by Úgaire son of Dúlang, king of Laigin, on Sitriuc son of Amlaíb, king of Áth Cliath, at In Deilgen Mo-Goróc.
A shower of wheat fell in Osraigi.
Aed ua Néill's son brought a raiding party over the Uí Dorthain who were in Mag Itechta, and they slew in Lethderg in the pursuit. And the best part of the Airgialla caught up with him from behind and came in front of him, or (as is stated in the Book of Dub dá Leithe) the Uí Méith and the Mugdorna and the Saithne and the men of Fernmag and the Uí Dorthain with their kings overtook him. Ua Ceilecháin and ua Lorcáin with the Uí Bresail and the Uí Nialláin, moreover, were waiting for him in Aenach Macha and they all surrounded him; and Aed's son took his spoils past them all, though he had only twelve score warriors. And a good number on both sides fell in the middle of Aenach Macha or Ard Macha. Thus in the book of Dub dá Leithe.
Branacán ua Maeluidir, tributary king of Mide, was drowned in Loch Ainnine on May Day.
Amalgaid, successor of Patrick, went to Mumu for the first time and made a great visitation.
Cellach ua Cathasaig, king of the Saithne, was killed by the Cenél Eógain.
The son of Flann son of Mael Sechnaill, i.e. Aed, heir designate of Temair, and Domnall ua Murchada, i.e. heir designate of Ailech, were killed.