Д10
ЗА ДАВНОСТЬЮ ЛЕТ (ВРЕМЕНИ)
PrepPthese forms onlyadvfixed WO (it is impossible to recall, determine etc sth. that existed or took place in the past) because so much time has passed since then
after so many (after all these) years
after all this time
sth. was (happened
etc) so long ago that...(in limited contexts) at this late date.