This very unusual surname is English and according to the famous Victorian etymologist Canon Charles Bardsley, writing in the year 1880, was specific to the county of Yorkshire. However he was later able to carry out further research in Northumbria which suggested to him that the name was of French origins, where he was told that the spelling was Teswicke. However in making this assumption we believe that he was in error. There is no name that we have been able to find in France which bears any resemblance to Teswicke, indeed 'wick or wic' is a pure Olde English term for a dairy farm. It is our opinion that Tyzack is a developed form of the Yorkshire place name Tyas as in Farnley Tyas, itself from the German (Anglo-Saxon) word 'tieis' meaning stranger. As such Tyzack or Tysack may well be a partronymic, that is to say the 'son of the stranger' from tieis + the Olde English word '-ock' meaning son of, or it may originate from a 'lost' mediebal village of farm called Tieis-wick' or similar. What we do know is that the name has been well recorded in the north of England over many centuries, and these recordings include John Teswicke of Newcastle, given as being a glass-maker, whilst in 1679 Abigail Tysacke, the daughter of John Tysacke was buried in the same city.