 John enjoyed the confidence of this doge, and was often sent as his ambassador to Holy Roman Emperors Otto III and Henry II.In the first part of his chronicle, which deals with the early period of the republic, the narrative is often confused and deficient; later it becomes more accurate and complete, and for the time in which the writer himself lived it is particularly valuable.He carries the narrative to 1008 and treats in detail of the reign of Pietro Orseolo.