See William of Malmsbury, de Gestis Anglorum, l. ii. p. 92.
Alexius fidem Anglorum suspiciens praecipuis familiaritatibus suis eos applicabat, amorem eorum filio transcribens.
Odericus Vitalis (Hist. Eccles. l. iv. p. 508, l. vii. p. 641) relates their emigration from England, and their service in Greece.