Every year, a running battle takes place on the streets of Sheffield when supporters of Yorkshire and Lancashire take each other on at the Bupa Great Yorkshire Run.
When you register you'll be asked to pledge your allegiance to your favourite county and we'll include a red rose or a white rose in your race pack, for you to wear on the day.
Yorkshire have been victorious for two years running, with TV stars Chris Chittell and Dean Andrews picking up the trophy for their county.
The winning county is calculated by the average finishing time of all runners competing the 10k course in a time of less than 70 minutes.
Come on…show your mettle in the steel city!