Complex sentence: The first and last meetings (in 1389 and 1989 respectively) bookend mirrored conversations criticizing two unpopular and resistance-inducing poll taxes: the instituted in the 1380s and the in the 1980s.
Split into simpler sentences: The first and last meetings (in 1389 and 1989 respectively) each has snippets of conversation that are very similar. For example, there're criticisms of two unpopular and resistance-inducing poll taxes, one instituted in the 1380s, the other in the 1980s.