There are two surviving poems in praise of King Llaenawc of Elmet's son,
Gwallawc the Battle Horseman, and it is one of these that
identifies the Kingdom which was ruled by his line. In En env
Gvledic nef gorchordyon, he is called "a judge over Elmet".
Gwallawc's reign was at its height in the late 6th century, when he
allied himself to his cousin, Urien Rheged, and his confederation
of British Kings that included Kings Morcant Bulc of Bryneich and
Riderch Hael of Strathclyde. Together, they caused much
discomfort to King Hussa of Bernicia and his men. Gwallawc was
present at the Siege of Ynys Metcaut, against him, in 590. It is
thought he may have contributed a sea-faring contingent to the
coalition.
