Legend has it that the Ostrich dates from 100BC, when the Romans were attacking Numidia, which is now Tunisia. Jugurtha, who was the King of the Numidians, put young warriors on ostriches who were so fast that they outflanked the Roman cavalry who subsequently fled the scene. The horseshoe in the Ostriches mouth is to show how they defeated the horses. This was apparently a well-known tale in Hungary & Romania.
It was later the crest of the Angevin Kings with Charles Robert, King of Hungary adopting it as his Crest and in particular, his son, Louis the Great of Hungary. Louis donated a chapel at Aix-le-Chapelle in the cathedral as a place of pilgrimage for Hungarians & this contains a large number of ostriches with horseshoes. Several of the tombs in Aachen Cathedral depict the ostrich.
Our records do not show how it came to be in the Digby family, although it has been the family crest since 1350 AD.