Ancestors, predecessors —i.e. those born before the present generation. (Anglo-Saxon, fór-béran.)
“My name is Græme, so please you,—Roland Græme, whose forbears were designated of Heathergill, in the Debateable Land.” —Sir W. Scott: The Abbot, chap. xviii.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894