The name Tachauer and/or Dachauer, is derived from the locality name in Bavaria, the town of Dachau. Nobility was always named by the area they owned. The name is also spelled with the letter D. From the earliest text, it was at the writers discretion which letter was used. 
Hence Tachauer = Dachauer, / Dachauer = Tachauer. This is widely documented.

In today's Germany, the letter "D" is the only one used. 

The letter "T" however, is retained and found in other parts of Europe, notably Austria and England. Also Argentina, Chile, Brazil, United States of America, and Canada.

Tachauer was a family of lower nobility who provided security for the Castle Dachau from the 12th century to the middle of the 14th century. First they were in charge of the Counts of Dachau, and beginning in 1181, the Bavarian Dukes of Wittlesbach. The family wealth in the 14th century included a large area of territory along the Amper river from Dachau to Furstenfeldbruck known as the Dachauer Moos. The family took their seat in the Castle of Lauterbach around the year 1330.

It is documented that another Ulrich (D)achauer (1427) and a brother Conrad were the last male members of the noble Tachauer family. At that time they were living in München. Ulrich was one of six knights and vassals of Duke Ernst (of Wittlesbach) who had been members of the "Bavarian" parliament. Landschaft was the name of the parliament at that time. Ulrich had no known children. His brother Conrad had only daughters. This brought an end to the original family. They married members of other noble families and divided up their property. The earliest members of the Tachauer family are buried at the monastery of Scheyern (still in existence). 

Family members who died after the year 1300 are buried at the monastery in Fürstenfeldbruck. 
 
 

Wie Gehts.
I am Jacques A. H. Tachauer, the youngest of seven sons of David H. Tachauer.
As a result of his parents being estranged, my father was sent to Canada at the age of nine and was placed in a foster home in southern Ontario. 

He settled in the city of Toronto, and lived there until his passing on November 30, 1948 at the age of 57. 

In World War One, he was an airman in the Royal Flying Corps. As an Observer, he flew with 16th squadron, in a Royal Aircraft Factory built R.E.8. 

In World War Two, he was a Captain in the Canadian Army.

Being four generations passed from land of origin, I am extremely pleased to have located and obtained the Tachauer coat of arms and its history. I acquired three copies of the coat of arms, which were crafted in Europe in 1982. Along with my two sons, Perry Aaron and Virgil Vernon, we proudly display one of these plaques in our respective homes. I trust they will be retained and passed down to and by my grandchildren through the years to come.