Professor Marged Haycock is a literary critic specialising in early Welsh poetry - the work attributed to the Cynfeirdd and the Gogynfeirdd - and is particularly interested in the variety of material surviving from the period between c.600 and c.1400.
A great resource for poems that are actually somewhat hard to find. Haycock presents each of the poems in a very interesting and helpful way, interspersing each line of Middle Welsh (which is bolded) with an English translation. This makes reading the text comparatively very light and easy, particularly for such a tough group of poems. Haycock's notes are extensive, focusing on linguistic difficulties and (to a lesser extent) interpretation and historical material. I personally hoped for more help on the latter two areas, as the poems are very difficult to understand. Even still, Haycock's translation, notes, and introductions are invaluable.
Professor Haycock's work translation and interpretation of the "Taliesin" poems is the first scholarly work on the entire body since Sir Ifor Williams decades ago, and though it owes much to the man's knowledge and understanding of the subject, Haycock was not handcuffed by his thoughts. It shows; her work goes a long way to understanding of the poems, the persona, and the times of Taliesin from post-Roman Britain up through the later Middle Ages. A must-have for anyone trying to understand post-Roman Britain.