[2] As his elder sons, Stephen I and Andrew I already appeared as office-bearers and active soldiers in the contemporary records since the 1320s, Lack presumably was born in the 1280s, thus his career began to rise when he was already relatively old.
[3] Lack first appeared in a contemporary royal charter in 1323, when he was already among the barons, who confirmed the peace treaty between Charles I of Hungary and Frederick the Fair with their seals.
Following the war, Lack was granted dozen landholdings in Arad, Hunyad, Csanád counties, laid surrounding the temporary royal seat Temesvár (present-day Timișoara in Romania).
[3] After his predecessor, Simon Kacsics was dismissed in 1327 or 1328, because he had committed "serious crimes", according to a contemporaneous royal charter,[3] Lack Hermán was appointed Count of the Székelys.
[5] He first appeared in this status with his seal ("Ladizlaus comes Syculorum") at the diploma of Charles on 21 September 1328, when the Hungarian monarch signed a peace treaty with the three dukes of Austria (Frederick the Fair, Albert the Lame, and Otto the Merry), who renounced Pressburg (now Bratislava in Slovakia) and the Muraköz (now Međimurje in Croatia).
[10] In addition, Lack styled himself the commander (captain) of the royal army stationed between the rivers Rába and Rábca during a campaign against Austria in 1336.
[11] Lack frequently resided in the royal court at Visegrád since the early 1330s, thus he exercised his duties and managed its accessory properties via his deputies.
This cooperation was temporarily overshadowed by a personal tragedy in early 1335, when Lack's son Emeric was murdered by three familiares of Szécsényi at the royal camp during Charles' campaign against Serbia.
Nicholas I, Paul, who held ispánates too, and Michael I also participated in King Louis the Great's royal campaigns, supporting their elder brothers.
Ladislaus I (or Lack) died early,[21] while Emeric I was murdered by Thomas Csapi from the Baksa kindred and two other noblemen during a 1334–1335 campaign against Serbia.
In May 1342, as a sign of conscious retirement, Lack and his wife have handed over their heritage to their five surviving layman sons (i.e. excluding the clergyman Denis), who shared the possessions among themselves in a contract.
[26] Lack lived a long time and witnessed the rise of his sons during the reign of Louis I, when eight members of the family held high offices.