The fifteens or fifteenth, as it is generally called, was originally an imperial tax levied throughout the kingdom for various purposes, as wars and such like.
It was a tax of one-fifteenth on movables of all kinds, and was of a similar nature to the tenths, thirteenths, fortieths, etc., which were so frequently levied during the 13th and 14th centuries.
It appears to have been levied by a careful valuation and assessment of the movable goods of each citizen in a city or township, whether clothes, jewellery, furniture, cattle, only certain specified goods being excepted, while the poorest citizens were in many instances exempt.
About the year 1334 the practice grew up of allowing the communities of cities and boroughs to treat with the royal commissioners appointed to assess and collect the tax and to agree upon a fine or sum to be paid as a composition for the fifteenth, tenth, etc., and the sum thus agreed upon was to be entered on the rolls as the assessment to the tax of that particular city or borough. Thus it came about that when a fifteenth was levied in subsequent years, no fresh assessment had to be made, and it was understood that the sum previously agreed upon would form the amount of the city's contribution. Thus the fifteenth came to be a convenient and well-understood unit of taxation.
The Letter Books of the City of London contain frequent references to the fifteens and we find the Mayor and Commonalty compounding with the royal commissioners in this way, and offering to pay £2000 or £3000, or whatever the sum might be that they thought would be acceptable as their contribution.
It is very interesting to compare the figures of different years. In the 8 Ed. II. there was a levy in the City of 1000 marks, and everyone assessed to the last fifteenth granted to the King to pay one mark in every £1 assessed and so more or less according as each was taxed in the said fifteenth (Cal. L. Bk. D. p. 307).
A careful comparison of the assessments of the various wards for fifteenths or fractions of fifteenths, etc., will show that in many instances the assessment of the wards remained unaltered from about the middle of the 14th century to the end of the 16th century, and each ward continued to contribute the amount at which it had been assessed originally, which was regarded as its fair proportion of the City's contribution (Cal. L. Bk. F. 3, 4).
In some of the later assessments, as set out in the Letter Books, it is to be noted that the totals contributed by certain wards do not correspond with the totals of these earlier assessments, whilst in others the totals are identical, and the same discrepancies are to be noticed in the figures of Stow's assessments as compared with those in the Letter Books.
Though in its origin an imperial tax, it is evident that in later times the City made use of the tax for its own purposes, as a convenient and easy method of raising a specified sum, for repair of walls, ditches, etc., and that a fifteen levied by the Mayor and Aldermen on the city was similar in amount to the same tax for imperial purposes.
The last fifteen was levied in 1624.