One of the greatest kings of Gwynedd was Owain Gwynedd, but his father Gruffydd ap Cynan can equally lay stake to such a claim.  His rule was certainly eventful.

Gruffydd ruled in Wales on and off since he was a young man, in between his flights to Ireland when the English—or other Welsh barons—ousted him from Gwynedd.  Gruffydd’s grandfather had been the King of Gwynedd once upon a time, and Gruffydd had claimed the throne as its lawful heir.

But staking his claim hadn’t been easy.  That first time, Gruffydd landed on Anglesey with an Irish and Danish, not Welsh, force.  After he defeated Trahaearn, the man who’d usurped his throne, Gruffydd led his army eastwards to reclaim territories the Normans had taken over during the unrest.  Despite the prior assistance given to him by the Norman, Robert of Rhuddlan, Gruffydd attacked and destroyed Rhuddlan castle.

Unfortunately for Gruffydd’s tenure on the throne, tensions between Gruffydd’s Danish-Irish bodyguard and the local Welsh led to a rebellion not long afterwards in Ll?n.  Trahaearn, the previously ousted King of Gwynedd, took the opportunity to counter attack—with a helpful Norman force—defeating Gruffydd at the battle of Bron yr Erw.

Not giving up, six years later in 1081, Gruffydd allied himself with Rhys ap Tudur, Anarawd’s grandfather, and tried again.  This time with a combined Dane, Irish, and Welsh force, he and Rhys marched north from Deheubarth to seek Trahaearn and his allies from Powys. The armies of the two confederacies met, Gruffydd and Rhys emerged victorious, and Trahaearn and his allied kings were killed. Gruffydd was thus able to seize power in Gwynedd for the second time.

But then the Normans counter-attacked, lured Gruffydd into a meeting near Corwen, and captured him.  They imprisoned him for sixteen years.  He finally escaped in 1197 and led a third invasion from Ireland.  After some ups and downs, and with the timely intervention of King Magnus of Norway, Gruffydd stumbled to victory, came to terms with the Norman Earl of Chester, and began to consolidate his power.   By the time his three sons were of age, he’d been King of Gwynedd for twenty years and had negotiated a peace with King Henry of England, who’d tried twice to conquer Gwynedd and failed.

This was the kingdom Owain Gwynedd inherited and the one he strived to defend and expand.

http://en.wikipedia.org/wiki/Gruffydd_ap_Cynan  http://www.earlybritishkingdoms.com/bios/gruffcgd.html