This thesis is based on the analysis of a single document, the Southampton Book of Fines (1488-1594), in the context of other Southampton documents and contemporary materials surviving in other towns. This thesis analyses the first half of the book (1488-1540), some 156 folios. The Book of Fines is a unique document which fills gaps in Southampton's documentary record at a time in the late fifteenth and early sixteenth centuries when the town was undergoing major economic change. It therefore contributes to a much better understanding of other elements in the archive. Critical analysis in this document of the period 1488-1540 is crucial to understanding the nature of mayoral income and expenditure and its effects on the town's economy during the Tudor period up to the Reformation This thesis argues, using the mayoralty of the instigator of the Book of Fines, Thomas Overay, as the benchmark, that the mayors of Southampton enjoyed considerable autonomy in the expenditure of monies accrued during their individual mayoralties. The funds that were collected under the Overay formula were available to individual mayors as a separate income stream from other town monies. This thesis explores ways which individual mayors prioritised this personal expenditure, thereby illuminating an aspect of town government for which the source material is unparalleled elsewhere in England.