Many thanks for the responses. The Greater Oxford dictionary confirmed, as many listers suggested, that Plow-Day = Plough-Monday, = the first Monday after Epiphany (the 6th Jan), and was the day on which the new Agricultural Year started after the holidays. I have since discovered that the practice of the ecclesiastics in York was to charge low rents but high entry fees (fines), which boosted their income if a tenancy was cut short by death or any other reason. Still haven't found why 11-year leases were routinely renewed after 5 years though. Colin