The D1 protein encoded by the psbA gene forms the reaction centre of photosystem II (PSII) and provides most of the ligands for binding the Mn4CaO5 cluster. Although the protein is conserved among cyanobacteria, five groups of D1 (G0-G4) have been identified, some of which (G0, G1 and G2) appear from sequence comparisons to be non-functional for oxygen evolution. The G1 group of D1, which contains so-called super-rogue versions of D1 (srD1), is expressed in cyanobacteria that synthesise chlorophyll f (Chl f) during far-red light photoacclimation (FaRLiP). Ho et al. (2016) have recently suggested that the srD1 is the chlorophyll f synthase (ChlF) and might form a homodimeric complex in the membrane, but the biochemical evidence is currently lacking. In this thesis I show that heterologous expression of srD1 encoded by the chlF gene of Chroococcidiopsis thermalis PCC 7203 in Synechocystis PCC 6803 leads to the production of Chl f. Two-dimensional (2D) polyacrylamide gel electrophoresis analysis of immuno-purified FLAG-ChlF indicated that ChlF forms a heterodimer with D2 and is incorporated into a novel type of monomeric PSII complex, termed the super-rogue PSII complex. Immunoblotting experiments and mass spectrometry revealed the presence of several low-molecular-mass subunits of PSII and Psb27. 77K fluorescence spectra of the isolated FLAG-ChlF complex showed a peak at 715 nm, consistent with the presence of Chl f. Characterisation of mutants lacking PSII core protein subunits indicated that the presence of CP43, CP47, and D2 was required for the accumulation of Chl f. Analysis of PSII activity in cells showed that the PSII complex containing ChlF was not functional for water oxidation, suggesting that this particular type of complex acts as a Chl f-producing PSII. Characterisation of chimeric D1 mutants containing portions of ChlF indicated that a QD motif in ChlF is vital for the production of Chl f. In addition, the chlF gene (3XFLAG-tagged) was successfully integrated into the Chlamydomonas reinhardtii chloroplast genome. Immunoblotting experiments of thylakoid membranes separated by 2D gel electrophoresis revealed that FLAG-ChlF was present in a large complex that co-migrated with a monomeric PSII fraction. Overall, this work identifies a new type of PSII complex which plays a physiological role in Chl f biosynthesis rather than water splitting.