After World War II., from among public collections, the Municipal Gallery was the first to open its doors to visitors, in 1946. In the summer of 1947, Jenő Kopp was followed by Gábor Ö. Pogány as the custodian of the gallery. Since the Municipal Gallery had in its ownership the best pieces of fine art from the previous one and a half century, the idea that the collection could form the basis of the creation of a new national gallery, started to take shape already in 1949. In the spirit of the establishment of a national gallery, the material bought by the Municipal Gallery based on “pure aesthetic principles”, was first merged into the National Picture Gallery collection belonging to the Museum of Fine Arts in 1953, and then, in 1957, into the collection of the Hungarian National Gallery. The “rest” of the material of local historical interest was placed at the Kiscelli Museum. With this, the first period of the Municipal Gallery came to an end.
Not much later, on the 18th of December 1959, however, the meeting of the Executive Committee of the Budapest Capital Council made a decision to restart the accessioning of works of fine arts. Starting from 1960, the capital allocated a sum for purchases, and, from 1961, the council entrusted the Budapest History Museum with keeping records of the collection. Between 1960 and 1973, accessioning was directed by the head of the Modern Department, Vilmos Bertalan. His immediate colleagues were Margit Egry Ferencné Tőkei and Péterné Cifka. Vilmos Bertalan hardly concealed his intention of reorganising the picture gallery and he managed to re-establish a historic collection, alongside the enlargement from living artists. Even though it was in these years that the masterpieces of the 19th century masters were obtained by the museum, accession still concentrated primarily on the 20th century, partly in the spirit of the reconstruction of the modern Hungarian arts collection that had been “taken away”. Works of great modern masters of the end and turn of the century, graphic art from between the two world wars and plastic art and paintings were acquired directly from the still living artists or from their heirs. With the support of the capital, alongside with works of local historical interest, an excellent Hungarian fine arts collection was built up remarkably quickly, the 20th century material of which mirrored – so to say, created on a collection level – the modernist story canonised after the fifties.
In 1973, important organisational and personal changes took place. Vilmos Bertalan was appointed deputy director-general of the Budapest History Museum, and the collection of the Modern Department was divided into two. A local history department and an independent, fine arts department (engraving collection, medal collection, graphic art collection, painting and sculpture collection) were formed. The later was entrusted to the care of Ferencné Tőkei, while the painting and the graphic art collection were lead by two young, art-historian-museologists, Emília Földes and Péter Zsolnay Mattyasovszky. Apart from obtaining relics of 20th century modernism, they were also open to the endeavours of the avant-garde and made efforts to collect the works of younger generations. In the spirit of the above, from the middle of the seventies, they managed to put together a significant collection from the works of the former artists of the European School, and, in 1980, part of the legacy of Lili Ország also arrived at the museum. From the late seventies and early eighties, principal works of the youngest generation – the most important works of the artists of the so-called Industrial Planning Group, i.e. a group of Hungarian neo-avant-garde artists included – also became part of the collection.
In the meantime, in 1980, once again, there were changes made concerning the leadership of the collection. Margit Egry Ferencné Tőkei was followed in her role by her former deputy, Emília Földes. Péter Zsolnay Mattyasovszky continued accessioning graphic art, the medal collection was overseen by Ágnes Krómer and the engraving collection by Anikó B. Nagy. In 1983, once the reconstruction of the building was finished, a fine arts exhibition displaying the complete collection was opened. From the middle of the eighties, the number of fine arts exhibits has increased. One of the highlights of these was the exhibition titled Temp-Rom-Tér – a pun on “church”, “ruin” and “interior” – organised in 1988. In the strange atmosphere of the interior of the church, which was in fairly bad shape at the time, the most modern material of the collection in the Kiscelli Museum was shown to both professionals and to the wider public. Not only did the exhibition achieve general success but it also brought about important changes. The capital decided to cover the costs of turning the interior of the church into an exhibition hall, and, in 1989, gave permission for the the fine arts collection to assume the name Municipal Gallery again.
The first permanent exhibition of the Municipal Gallery opened on the 24th of March 1992, on the first floor of the Kiscelli Museum. In the same year, the renovation of the church interior was finished and, in harmony with the original conception, it gave room to the temporary exhibitions of the Municipal Gallery. The preparation for and then later the opening of the permanent exhibition provided a good opportunity to overview the accessioning of the previous decades, to appraise the virtues and vices of the collection and to give careful thought to future accessioning procedures and practices. As a result of a number of “long-needed” purchases, the material of the 60s and 70s was enriched by significant pieces, occasionally masterpieces, and the enlargement of the 80s collection continued. From 1996, Emília Földes worked as the assistant manager of the institution, until her death in 2002. Péter Zsolnay Mattyasovszky oversaw the graphic art collection of the museum of the Gallery until 2014.