The ‘tours’ (towers) Leland refers to may have been simply showy pieces of domestic architecture, after all what could have been more ‘showy’ than an eye-catching tower rising well above the general roofline.
However, there may have more prosaic purposes. For example, they would have enabled the ‘Old Harbour’ and the middle Humber Estuary to be viewed and, seeing as M. De la Pole is unlikely to have lived in all four properties at once (Suffolk Palace and three other houses, s.p.b.), and if rented-out the most likely tenants would have been local merchants, they (the upper storey of the towers) may have functioned as look-out points to observe shipping as well as their loading and unloading. There are other examples in Humberside of domestic towers built to give a view of shipping, the ones that come to my mind are one at Hilston (view of coastal shipping), one at Alkborough (views over the upper Humber and Trent Falls) and one at Easington. In a sort of ‘big brother’ way the towers may also have afforded a vantage point from which to survey goings-on in the town. The photo above shows Trent Falls in the middle distance, picture taken from point above Welton Dale.
The vexatious question of local authority (government) through the ages was an issue highlighted by early travelogue writers. Leland writes (unfortunately this paragraph on p. 11 of Descriptions of East Yorkshire: Leland to Defoe, s.p.b.s is badly stained) that he had been told that ‘their first great corporation was grayntid to Kingeston’ in 1360 (?). He also states that in the past Hull had ‘bailives’, then ‘maire and bailives’ and in the reign of Henry ? ‘a maire, a shirive, and the toun to be shire ground by itself’ (Hullshire). Fortunately E. Gillett and Ken MacMahon dealt with this issue more thoroughly for late medieval and early modern times in Chapter 7 of A History of Hull (Hull University Press, 1980).