The stately foundation of Moldavia and of Wallachia, Iorga thought, were linked to the emergence of major trade routes in the 14th century, and not to the political initiative of military elites. Likewise, Iorga looked into the genesis of boyardom, describing the selective progression of free peasants into a local aristocracy. He described the later violent clash between "hospodars" and boyars as one between national interest and disruptive centrifugal tendencies, suggesting that prosperous boyardom had undermined the balance of the peasant state. His theory about the peasant nature of Romanian statehood was hotly debated in his lifetime, particularly after a 1920 discovery showed that Radu I of Wallachia had been buried in the full regalia of medieval lords. Another one of his influential (but disputed) claims attributed the appearance of pre-modern slavery, mainly affecting the Romani (Gypsy) minority, exclusively on alien customs borrowed from the Mongol Empire. Iorga's verdicts as a medievalist also produced a long-standing controversy about the real location of the 1330 Battle of Posada—so-named by him after an obscure reference in the "Chronicon Pictum"—whereby the Wallachian Princes secured their throne.