This two-volume work contains documents from the Venetian state archives from the period 1300–1454. They refer to Venice's dealings with her own empire across the eastern Mediterranean and with foreign powers, including Turkish sultans and Byzantine emperors. At that time, Venetian power was at its zenith (the doges boasted of being rulers of 'one-quarter and one-half of a quarter of the whole world'), but there were dangers to Venetian naval and mercantile supremacy from the continuous advance of the Ottoman Turks across the territory formerly ruled from Constantinople. Volume 1, edited by the German scholar G. M. Thomas (1817–87) and published in 1880, covers the period 1300–50. The first document, from 1301, refers to the gathering of troops for military action against Constantinople, while the last is a message from Pope Clement VI begging the doge to join a union against the Turks.