Isidore of Seville, who died on 4th April 656AD, spans the classical and medieval worlds. Besides being bishop of Seville (from about 600 to his death), he also attempted to condense huge amounts of classical learning into his most famous work, the Etymologies. This huge reference work was very influential throughout the Middle Ages, and explains why Isidore was selected by Pope John Paul II as the patron of the internet. A good summary of Isidore’s life and of the Etymologies, including images from various manuscripts of the work, is available on the British Library website .
The importance of Isidore can be seen in the fact over a thousand manuscript copies of the Etymologies survive and it was one of the first printed books. Almost certainly available in all cultural centres by 800AD, it seems to have arrived particularly early in Ireland. The earliest fragments of the Etymologies is housed in St Gall (named for the disciple and companion of Saint Columbanus). Written in an Irish scribal hand, it may date back as far back as the mid seventh century. References in Irish texts show that the Etymologies was certainly known in Ireland by the late seventh century and by 700AD all but one of Isidore’s works had arrived in Ireland.