This thesis is a monographic analysis of Alvar Aalto’s (1898–1976) Church of the Three Crosses (1955–58) in Imatra, Finland.

This thesis shows that the design and construction of the Church of the Three Crosses involved concerns and themes unique to, or especially relevant in, the ecclesiastical context, and that their influence is legible in the architecture of the building itself. The thesis enriches previous assumptions which hold that Aalto’s religious projects were primarily opportunistic undertakings unrelated to religious discourse. It illustrates how the Finnish national Lutheran Church, its local parishes, national and local governments, industry and the Aalto atelier came together to build modern religious architecture. The thesis argues that religious influences were not extrinsic or peripheral to architectural modernism, but intrinsic and intimately related to it.

The Church of the Three Crosses stands at the centre of the thesis, but is interrogated with reference to Aalto’s other religious projects, both realised and unrealised. The Church of the Three Crosses is analysed in light of previously unstudied archival sources and in situ analysis of the realised building itself. Material from church and parish archives sheds light on the religious issues that influenced the design of the Three Crosses, and vice versa, whereas material from municipal archives elucidates their political underpinnings. Archival material from the Alvar Aalto Museum, in turn, helps qualify how and where these influences—their incorporation, reinterpretation, adaptation or rejection—can be seen in the resultant building.

The core concern of the thesis is the building of the Three Crosses understood as both noun and verb: the church building as a piece of architecture, and the processes of commissioning, designing and constructing it. The thesis argues that the Three Crosses’ architecture, like that of Aalto’s other ecclesiastical commissions, neither straightforwardly rejects nor complies to the religious dogma, policies and ambitions of the client parish. It shows that Aalto’s involvement with the national Church transcended mutual opportunism, and should, more accurately, be described as a consciously and productively symbiotic partnership, encompassing both compromise and conflict. Their collaboration allowed both parties to further their own agendas—in the religious and architectural realms—and, together, build modern religious architecture.