They often depicted the Tuath Dé as kings, queens and heroes of the distant past who had supernatural powers or who were later credited with them.[7] Other times they were explained as fallen angels who were neither good nor evil.[8] However, some medieval writers acknowledged that they were once gods. A poem in the Book of Leinster lists many of them, but ends "Although [the author] enumerates them, he does not worship them". The Dagda's name is explained as meaning "the good god"; Brigit is called "a goddess worshipped by poets"; while Goibniu, Credne and Luchta are referred to as Trí Dé Dána ("three gods of craftsmanship"),[9] Characters such as Lugh, the Morrígan, Aengus and Manannán mac Lir appear in tales set centuries apart, showing all the signs of immortality.