The Type 21 Frigate is a class of warship designed for the British Royal Navy in the 1970s. These vessels were primarily built for anti-submarine warfare and were equipped with advanced sonar systems and weapons. The Type 21 Frigates were notable for their speed and agility, making them effective in various naval operations. Constructed with a focus on cost-effectiveness, the Type 21 Frigates featured a simple design and were relatively easy to maintain. They served in the Royal Navy until the late 1990s and were succeeded by more modern classes, such as the Type 23 Frigate.