Niketas Choniates, 12-13th c. Byzantine historian and court functionary. His account centres around the crusader sack of Constantinople in 1204 and how it is all the fault of the Komnenoi and some bad Angeloi and definitely no blame should be applied to Niketas Choniates, who had some sort of senior position in the government of the latter. After the establishment of the Imperium Romaniae by the crusaders he went to the nascent Laskarid court in Asia Minor, where he failed to find much sympathy despite writing some encomiastic orations about Theodore I Laskaris and a major theological work (which was likely a commission by the government).
“History of Portugal: 1st period, from the origin of the monarchy to D. Afonso III” - 1846-1853
“History of the Origin and Establishment of the Inquisition in Portugal” - 1854-1859
“Portugaliæ Monumenta Historica” - 1856-1873 (collection of primary sources)