Задание 19 ЕГЭ, английский язык: Грамматические навыки

Преобразуйте, если это необходимо, слово TWENTY так, чтобы оно грамматически соответствовало содержанию текста.

For more than 800 years the castle was a fortress against the English and rival Scottish clans. For the most part it was in a state of neglect since then. About 150 years ago it became a luxurious farm house and then in the early part of the ______ century it became a hunting and fishing lodge.