Today’s City of Toronto takes in much more territory than it did when it was incorporated in 1834. The following simplified chronology explains some of that growth.
| 1788 | Nassau District is formed, including the area that would become Toronto. |
| 1791 | The townships that would become Scarborough, York and Etobicoke are surveyed along the shore of Lake Ontario (within Nassau District) |
| 1792 | Nassau District’s name is changed to Home District. |
| 1792 | Counties (for militia purposes) are set up within districts. Toronto is in York County. |
| 1793 | Town of York is founded on August 27 (within York Twp.) |
| 1834 | Town of York, with a population of about 9,000, is incorporated as the City of Toronto (March 6) |
| 1850 | Districts are abolished; governmental control shifts to counties, with representation from each township. (York, Scarborough, Etobicoke and Toronto are in York County.) |
| 1853 | Village of Yorkville is founded (severed from York Twp.) |
| 1878 | Town of Parkdale is founded (severed from York Twp.) |
| 1880 | Village of Brockton is founded (severed from York Twp.) |
| 1881 | Village of Weston is founded (severed from York Twp.) |
| 1883 | Yorkville is annexed by Toronto. |
| 1884 | Brockton is annexed by Toronto. |
| 1887 | Town of West Toronto Junction is founded (severed from York Twp.) |
| 1889 | Parkdale is annexed by Toronto. |
| 1889 | Town of East Toronto is founded (severed from York Twp.) |
| 1889 | Town of North Toronto is founded (severed from York Twp.) |
| 1909 | West Toronto Junction is annexed by Toronto. |
| 1911 | Mimico is founded (severed from Etobicoke) |
| 1912 | East Toronto is annexed by Toronto. |
| 1912 | North Toronto is annexed by Toronto. |
| 1913 | Leaside is founded (severed from York Twp.) |
| 1913 | New Toronto is founded (severed from Etobicoke) |
| 1922 | Township of North York is severed from York Township (June 13) |
| 1923 | Township of East York is severed from York Township. |
| 1923 | Village of Forest Hill is founded (severed from York Twp.) |
| 1925 | Village of Swansea is founded (severed from York Twp.) |
| 1931 | Long Branch is founded (severed from Etobicoke) |
| 1953 | A second-tier municipality “Metropolitan Toronto” is formed to govern some aspects of life in Toronto, York, East York, North York, Etobicoke, Scarborough, Swansea, Forest Hill, Weston, Leaside, Mimico, New Toronto, and Long Branch. |
| 1967 | Etobicoke, Long Branch, Mimico, and New Toronto amalgamate to become the Borough of Etobicoke. |
| 1967 | Village of Forest Hill is annexed by Toronto. |
| 1967 | Village of Swansea is annexed by Toronto. |
| 1967 | York Township amalgamated with Weston to become the Borough of York. |
| 1967 | North York Twp. becomes the Borough of North York. |
| 1967 | East York and Leaside amalgamated to become the Borough of East York. |
| 1967 | Metropolitan Toronto now includes Toronto and the boroughs of York, East York, North York, Etobicoke, and Scarborough. |
| 1979 | North York becomes a city. |
| 1983 | Borough of York becomes the City of York. |
| 1983 | Etobicoke becomes the City of Etobicoke. |
| 1983 | Scarborough becomes the City of Scarborough. |
| 1998 | Toronto, Etobicoke, Scarborough, York, East York, and North York amalgamated as the City of Toronto. |