 Óláfs saga Tryggvasonar en mesta

Óláfs saga Tryggvasonar en mesta or The Greatest Saga of Óláfr Tryggvason 
is generically a hybrid of different types of sagas and compiled from various sources in the fourteenth century, but is most akin to one of the kings' sagas.It is an extended biography of King Óláfr Tryggvason and relates in detail the conversion to Christianity of Óláfr Tryggvason and Hallfreðr vandræðaskáld.