The beginning of Book I of Bede's Historia Ecclesiastica. From the early 12th-century manuscript Harley 3680, in the British Library.
The manuscript was created by two scribes in the cathedral priory of St. Andrew in Rochester in the 12th century. The script is protogothic. The decorated initial "B" begins the word "Brittania." For a detail of the decorated initial, click here.
Image source: British Library Catalogue of Illuminated Manuscripts