According to Simon of Kéza's "Gesta Hunnorum et Hungarorum", Reynold and his brothers, Andrew, Solomon and Ladislaus bravely fought in the Battle on the Marchfeld on 26 August 1278, where Ottokar II was killed. During the skirmish, Reynold kept and guarded the royal banner. While "magister" Simon described the events of the battle, he detailed exclusively the heroism of the Básztély brothers; therefore notable historians, like Gyula Pauler and Sándor Domanovszky considered that the chronicler originated from Dunakeszi, which belonged to the ownership of the clan. Despite Reynold's loyalty and military skills, he did not hold any dignities in the royal court for the next decade, albeit it is presumable that he is identical with that Reynold, who was styled as "ispán" of Valkó County in 1279.