A Viking fleet of about 120 ships under Turgesius invades kingdoms on Ireland's northern and eastern coasts.
Clondalkin was sacked by Vikings from Denmark and the monastery was burned to the ground.
833
Death of Conchobar mac Donnchada, King of Mide and High King of Ireland with opposition.
836
Viking raids penetrate deep inland.
837
Large Viking fleets appear on the River Boyne and the River Liffey, made up of sixty ships at each location.
838 - 841
A small Viking fleet enters the River Liffey in eastern Ireland, probably led by the chieftain Saxolb (Soxulfr) who is killed later this year. The Vikings overwinter on Lough Neagh in 840 and set up a base, which the Irish call longphorts and which will eventually become Dublin.
839
Thorgest (in Latin Turgesius) is the first Viking to attempt creation of an Irish kingdom. He sails up the Shannon and the Bann to Armagh where he forges a realm spanning Ulster, Connacht and Meath.
Viking army defeated near Cashel by Ólchobar mac Cináeda.
Vikings at Cork; besieged by Ólchobar mac Cináeda.
The Annales Bertiniani report the arrival of Irish envoys at the court of Frankish EmperorCharles the Bald. They bring gifts from the "king of the Irish" and announced an Irish victory over Vikings. The Irish annals record several defeats for Viking armies; which of these is meant is unclear. The identity of the "king of the Irish" is no more certain, but Ólchobar mac Cináeda may be intended rather than Máel Sechnaill.