Isidore begins his history with a prologue, Laus Spaniae, praising the virtues of Spain.
The rest of the work elaborates and defends the Gothic identity of a unified Spain.
The main source for his early history was Jerome's continuation of Eusebius to the year 378.
Victor of Tununa is his primary African witness for the years 444 to 566 and John of Biclar for recent Spanish history (565–90).
The edition of the longer version by Theodor Mommsen is the standard[2] and was the basis of the first English translation.