The surname Crosthwait was first found in Cumberland.  While technically in England, Cumberland (Cumbria) is actually on the Scottish Borders, an area of conflict for centuries between the Scottish and the English.
As far as early records of the family are concerned, they are indeed few as we only found one record of the family in the Hundredorum Rolls of 1273: John de Crostweyt and this was a family in Norfolk. 
Early History of the Crosthwait family
This web page shows only a small excerpt of our Crosthwait research. Another 104 words (7 lines of text) covering the years 1534, 1729 and 1721 are included under the topic Early Crosthwait History in all our PDF Extended History products and printed products wherever possible.
Crosthwait Spelling Variations
Spelling variations of this family name include: Crossthwaite, Crosthwaite, Crosswaith, Crosswaite and others.
Early Notables of the Crosthwait family (pre 1700)
More information is included under the topic Early Crosthwait Notables in all our PDF Extended History products and printed products wherever possible.
Migration of the Crosthwait family to Ireland
Some of the Crosthwait family moved to Ireland, but this topic is not covered in this excerpt. Another 30 words (2 lines of text) about their life in Ireland is included in all our PDF Extended History products and printed products wherever possible.