Blake wrote Tiriel in or around 1789. It can be seen as poem of lamentation, and the figure of Tiriel, an aged king who has been exiled from his own land, as a version of King Lear. Here, however, the resemblance stops, for the reader is not expected to sympathise with Tiriel in his plight but rather to see it as an inevitable outcome of misrule and arrogance. Tiriel has enslaved his brother Zazel and cursed his own children; small wonder, then, that his attempts to find solace – in, for instance, his visit to his own parents Har and Heva – meet with no success. In the poem Blake is clearly depicting the fate of tyranny in terms that readily connect with themes of exile and wilderness drawn from biblical sources.
Punter, David. "Tiriel". The Literary Encyclopedia. First published 17 July 2001
[http://www.litencyc.com/php/sworks.php?rec=true&UID=8366, accessed 27 February 2017.]