sentences:  This unique requirement, at such a late stage in history, has made the palace at Monaco one of the most unusual in Europe.Indeed, when its fortifications were finally relaxed during the late 18th century, it was seized by the French and stripped of its treasures, and fell into decline, while the Grimaldi were exiled for over 20 years.The Grimaldis' occupation of their palace is also unusual because, unlike other European ruling families, the absence of alternative palaces and land shortages have resulted in their use of the same residence for more than seven centuries.