Wikipedia
Habersack is a family name. The earliest records of the Habersack family originate in Germany. The name is derived from the word " haversack"- another name for a rucksack or backpack- which is mostly an English usage of the word, but an older definition of the word is a feeding bag for a horse that is suspended from the bridle.
The earliest known Habersack on record was a Johan Haversac who lived in Hamburg in 1272. Thilo Haversack is mentioned in the town records of Braunschweig in 1306; Canellen Haversackes in Neuhaldensleben/ Saxony in 1330; and Henslinus Hawersak 1413 in Saaz/ Bohemia. Name spellings change according to phonetics and convenience. There is every reason to believe that variants such as Haversack, Haversac, Habersackin are in some form related, as they show up later in genealogical records than Habersack.
Another early record of a Habersack comes from the era of Maximillian II, Holy Roman Emperor in the 16th century. In a sideline to history, a Hans Habersack is mentioned in the years around 1554-1574 of Vienna, Austria. During the reign of the Habsburgs of Austria, the Habersack family was tied by marriage to the royal family, as well as a family named Buschbacher. The distance between the families in Europe may have its roots in the 30 Year's War and differences in faiths of the families.