Athirne Ailgheasach or Athairne the Importunate was a poet and satirist of the court of Conchobar mac Nessa in the Ulster Cycle of Irish mythology, and he was the son of Fer Chedne(Ferchertne). He was the foster-father of Amairgin mac Echit, who succeeded him as Ulster's chief poet.
Athirne abused the privileges accorded to poets, demanding the remaining eye of a one-eyed king, or sexual favours from women in childbirth, provoking wars the Ulaid had to fight. He stole three cranes from Midir, which stood at his door and refused entry or hospitality to anyone who approached.
Athirne and his two sons all fell in love with Luaine, who was due to marry Conchobar. When she refused them, Athirne made a satire on her which left three blotches of shame, blemish and disgrace on her face, and she died (or possibly committed suicide) out of shame. Conchobor gathered the heroes of Ulster, walled Athirne into his house and burned it down, killing him and his entire family.
Books that discuss Athirne
The following are just some of the books where Athirne is one of the characters.
- Talland Etair - The Siege of Howth, English translation here 
- Athirne Áilgessach & Mider Brí Léith
- Athirne and Amairgen son of Ecet Salach
- Aigidecht Aithirne
- http://www.ucc.ie/celt/published/G800011B/text004.html - Incipit Talland Etair (The Siege of Howth)