The beginnings of the Whittlesea line occurred during its opening on 8 October 1889, as part of railway extensions into the northern suburbs.

[1] Trains on the line operated via Fitzroy and the Inner Circle, until the opening of the current connection between Victoria Park and Princes Bridge stations in 1901.

[2] The remaining numbered RMSPs (8, 9, 10, 17, 26, 33, 34, and 39) were all closed on 29 November 1959 with the closure of the line past Lalor station.

From this time, a double-ended Leyland railmotor was provided, and connections made at Thomastown.

However, the right-of-way beyond Mernda is still in place, and is retained for a future railway extension.