I have both Cyr and St. Cyrs, what is the history of the differences

Question

  Albert St. Cyr was born in 1822 in Nicolet, Bas-Canada born in 1822 in Nicolet, Bas-Canada: his son,

Nelson Narcisse H. (Nelson) Cyr Nelson H. Cyr (1845-1931

Answer 1

there are a number of men who migrated here whose name is standardized by PRDH as Cyr, PRDH CYR pioneers list (just enter Cyr in the box and press enter), the majority listed actually being from Acadie (PRDH in this listing includes any men not born in this province's territory who had male descent).

St-Cyr stems from the Rouillard family, and the Deshaies  family, who had it as a dit name.  There is also Claude Cécire whose name sometimes gets heard and written as St-Cyr.