The building was designed by John Ensor and constructed as part of the Rotunda Hospital in 1764 as an assembly hall and social rooms on what is now called Parnell Street.

[1] From 1897 onwards, the venue was given the name Rotund Room and hosted a number of moving picture screenings, which were a great novelty at the time.

From about 1908 onwards, it was used more regularly to show film presentations and in 1910 it became a full-time cinema, with 736 seats, a basic layout at the time.

[citation needed] In 1977, the cinema was forced to close briefly, but it reopened that summer under new ownership.

The Green Group ran the cinema until 1988, and it mainly played children's films such as The Care Bears Movie and its sequels.

Entertainment promoters MCD Productions leased the building and for a number of years ran The Ambassador as a live music venue, until 2008.