This thesis addresses three outstanding areas of inquiry regarding the impact of systematic, synthetic phonics teaching following the introduction of the Year 1 Phonics Screening Check in England. These areas of inquiry concern the following key questions: (i) has this increased emphasis on phonics teaching impacted early reading performance and emerging reading difficulties (ii) do phonics-taught early readers have the skills to “self-teach” grapheme-to-phoneme-correspondences? The first study compared two secondary datasets, to determine whether reading performance for different word types, indicated differences between a pre-phonics and post-phonics sample. The post-phonics sample was longitudinal which also enabled an examination of changes in performance for different words over time. The second study utilised the same data, to determine whether emerging profiles of reading difficulty differed between the pre-phonics and post-phonics samples. Stability of these profiles of reading difficulty were also examined. The third study was a novel experimental training study with Reception and Year 1 children (n = 126). The aim was to determine whether beginner readers who were already receiving synthetic phonics teaching could “self-teach” unfamiliar grapheme-to-phoneme-correspondences and generalise these to novel words. Literacy-related skills and the role of context on this learning ability were also examined. Overall, the key findings were that firstly, the post-phonics sample outperformed the pre-phonics sample longitudinally when reading both word types. Additionally, the post-phonics sample displayed fewer profiles of reading difficulty than found within the pre-phonics sample, when allocated with the same measures. Limited stability was found for early reading difficulties, with Exception and Mixed profiles displaying more stability than Nonword profiles. Finally, early readers taught through phonics and with adequate phoneme awareness, letter-sound knowledge and vocabulary, were able to “self-teach” novel grapheme-to-phoneme-correspondences. In conclusion, this thesis contributes new evidence of the beneficial impact of phonics teaching in reducing difficulties and increasing independence in reading.