Author of a pioneering study on medieval southern Italian art; professor of art history. Bertaux attended the Institut Sainte-Croix at Neuilly and the Lycée Condorcet in Paris. At the École normale supérieure, where he was a student from 1888 to 1891, he earned the degree of agrégé de lettres. After his military service he studied the art of the Italian renaissance under Eugène Müntz in Paris. In 1893 he enrolled at the École française de Rome, housed at the Palazzo Farnese.

Specialist in medieval Italian and Byzantine art. Dobbert's father was medical doctor assigned to imperial Russia, James Dobbbert. The younger Dobbert was raised in St. Petersburg. Dobbert entered at the University of Tartu, in Estonian Russia in 1857, but the following year he moved to Jena, studying history under Johann Gustav Droysen (1808-1884) and philosophy under Kuno Fischer (1824-1907).

Architect and architectural historian. Hubbard was the son of John Waddington Hubbard, M.R.C.S., L.S.A. (1823-1871) and Emma Evans (Hubbard). He married Sarah Eleonora Rouquette in 1892. Fellow of the Royal Institute of British Architects (FRIBA)

Early historian of medieval Christian art. Willibald Sauerländer included Martin among the "pantheon of great [early] art historians" of medieval art whose numbers included Adolphe Napoléon Didron, Charles Cahier, Ferdinand Piper and Franz Xaver Kraus.

Scholar of Christian iconography; Renaissance religious art; cultural sources and currents within Gothic Italian Gothic forms (particularly sculpture); Spanish art history (sculpture); Max Dvořák influenced; professor at the University of Tübingen (1923-1951). Weise's Das Formleben der gotischer Ausdrucks- und Bewegungsmotive in der Kunst des Manierismus (1954) owes much to Walter F. Friedländer and his concept of Mannerism as "anti-classical" (i.e., akin to gothic tendencies (Posner).