Born in an aristocratic family, he studied at the University of Padua before joining the War of the Portuguese Succession on the side of King Philip II of Spain.

After his return, Lassota was promoted to Inspector General of Upper Hungary, a position he kept until the uprising of Stephen Bocskai in 1604, when his property was despoiled by the rebels.

The exact date and place of birth of Erich Lassota von Steblau are unknown; it has been assumed that he was born around 1550–55 and very probably in Błażejowice (known as Bleischwitz in German) in Silesia, where his family's main estate was located.

[6] Erich Lassota von Steblau received basic schooling in Görlitz (c. 1567) and in 1574–1576 he studied at the University of Padua in Italy.

[2] He then returned to his father's estate, but in 1579 set out to participate as a soldier in the War of the Portuguese Succession on the side of King Philip II of Spain as part of a regiment consisting of German-speaking nobles.

[1] He spent five years in the army, fighting in the Iberian peninsula as well as participating in the conquest of the Azores, before taking his leave in Italy in 1584.

[7] Following their release in 1590, Erich Lassota von Steblau was sent on a covert mission to Moscow in order to try to establish an alliance with Russia against Maximilian's Swedish rivals.

He kept this position until 1604, when the city of Košice was plundered during the uprising of Stephen Bocskai, and Erich Lassota von Steblau's property despoiled.

[11] The original manuscript of the diary is kept in the city library of Bautzen in Germany, where it forms part of collections donated by Hans von Gersdorff (1630–1692).