RCMP's predecessor was NWMP (North-West Mounted Police), and was then awarded "Royal" title by King Edward VII of England in 1904. Later it was renamed as RCMP.
RCMP is Canada's natinal police force, and also acts as provincial police, under contract, in all other provinces and territeries EXCEPT Ontario, Quebec and Newfoundland, where they have their own police forces - the Ontario Provincial Police, La Surede du Quebec, and Roayl Newfoundland Constabulary (RNC) respectively. RNC only provides policing to large cities of Newfoundland and Labrador, while RCMP polices all other communities in the province.
That's why you have to report to RCMP for car thefts in BC, but to "local" police in Ontario.