Its existence and toughness provided a principal base of operations for pirates in the Caribbean.

The corsairs later would make Algiers their principal base.

From then on, it was the principal military base of the British.

The polls show that the white women who ought to be her principal base of support favor her opponent by five percentage points.

It also serves as Virgin America's principal base of operations.

Its principal base is in trade unions, where leaders often complain about restrictions on their ability to organize.

Sodium hydroxide is the principal strong base used in the chemical industry.

It is the principal base for mine warfare vessels.

There are two principal bases upon which it could be demonstrated that the evidence would have been discovered.

Plans to attack New York were abandoned, and it remained the principal base for British forces until 1783.