For a period of almost five hundred years York Minster resembled a building site as different parts were added and altered before it finally became the building we see today. This detailed study of the construction and development of the minster draws on architectural recording carried out on the building by the RCHME and English Heritage since the early 1970s, as well as more recent discoveries and research, particularly on the stained glass windows. Each major building phase is discussed in turn: the construction of the transept, the Chapter House, the nave, Lady Chapel, western choir and central tower. The historical background to these phases reveals some of the financial, political and religious events that hampered and/or motivated the building phases and this, and issues of imagery and patronage, are all discussed.