In the ensuing centuries, right up the present, the Walls were to crucially influence the city's history; firstly as a physical barrier, when the city successfully withstood a number of sieges and particularly that of 1688-89, which helped secure the protestant colonial settlement of Londonderry. A secondary effect is the potency of the Walls as a symbolic representation of the political, cultural and religious differences, which were ushered in with the creation of the colonial city.