The surname Jendrusch has its origins in the Slavic regions of Eastern Europe, particularly in Poland and parts of Germany where Slavic influence was strong. It is believed to have emerged sometime during the Middle Ages, likely between the 11th and 13th centuries.

The name Jendrusch is thought to be derived from the Slavic root word "jędra," which means "strong" or "sturdy." This suggests that the name may have originally been given as a descriptive nickname to someone who was perceived as being physically robust or resilient.

While there are no definitive records of the name appearing in major historical documents like the Domesday Book, some of the earliest documented instances of the Jendrusch surname can be found in Polish and German parish records dating back to the 16th and 17th centuries.

One of the earliest known bearers of the Jendrusch name was Jan Jendrusch, a Polish landowner and farmer who lived in the village of Grabów near Częstochowa in the late 16th century. Records suggest that he was born around 1560 and owned a sizable tract of land in the region.

Another notable individual with the Jendrusch surname was Kasper Jendrusch, a German merchant and trader who lived in the city of Gdańsk (formerly known as Danzig) in the early 17th century. Kasper Jendrusch was involved in the Baltic Sea trade and is believed to have established business connections with merchants in various ports across Northern Europe.

In the 18th century, there was a Polish nobleman named Jerzy Jendrusch, who served as a military officer in the Polish-Lithuanian Commonwealth. He was born around 1720 and is known to have participated in several military campaigns against the Ottoman Empire and Russia.

Another individual of note was Anna Jendrusch, a German-born artist who lived in the late 19th century. She was a skilled painter and is known for her portraits and landscapes depicting rural scenes from her native region of Silesia.

Finally, in the early 20th century, there was a Polish educator and writer named Tomasz Jendrusch, who was born in 1885 and spent much of his career working as a teacher and headmaster in various schools in the Kraków region. He also published several books on educational philosophy and pedagogy.

It is worth noting that variations in the spelling of the Jendrusch surname may have existed over time, with alternative forms such as Jendrusch, Jendruschek, or Jendruszczak being used in different regions or historical periods.