Boroughs of New York City
All five boroughs of New York came into existence with the creation of modern New York City in 1898, when New York County (then including the Bronx), Kings County, Richmond County, and part of Queens County were consolidated within one municipal government under a new city charter. All former municipalities within the newly consolidated city were dissolved.
New York City was originally confined to Manhattan Island and the smaller surrounding islands that formed New York County. As the city grew northward, it began annexing areas on the mainland, absorbing territory from Westchester County into New York County in 1874 (West Bronx) and 1895 (East Bronx). During the 1898 consolidation, this territory was organized as the Borough of the Bronx, though still part of New York County. In 1914, Bronx County was split off from New York County so that each borough was then coterminous with a county.
When the western part of Queens County was consolidated with New York City in 1898, that area became the Borough of Queens.