Here's what we know:
* Roman legions used dogs resembling Rottweilers to herd cattle and guard property. These dogs were likely a combination of various breeds.
* The Rottweiler's name comes from the German town of Rottweil. This suggests their development as a distinct breed occurred in that region.
* They were likely used for butchering and guarding by butchers in Rottweil. The breed's strong build and protective nature made them ideal for these roles.
* The Rottweiler's official recognition as a breed happened in the late 19th century. This marks a point where the breed had been established and standardized.
Therefore, while the exact date of their initial domestication is unknown, it's safe to say Rottweilers have a long history dating back to ancient Rome. Their development into a recognized breed took place over centuries in the region of Rottweil, Germany.