The Cook Islands, a sovereign state in free association with New Zealand, uses two official legal tender currencies. The New Zealand Dollar circulates in parallel with the local Cook Islands Dollar; at the same time, the government also authorises many legal tender coins in the Cook Islands Dollar currency for collector's purposes.
Collector coins are dedicated to historical or general popular culture themes not related to the country itself. Many of them are in bullion sizes based on the troy ounce, but some are "metric", like twenty-five grams (25g) of silver.
This coin is part of the History of the Crusades series and is dedicated to The Sixth Crusade and Frederick II, Holy Roman Emperor.
The Mint says about it:
The Crusades were a series of religiously sanctioned military campaigns waged by much of Latin Christian Europe, particularly the Franks of France and the Holy Roman Empire during the 11th to 15th century. Each coin depicts a unique scene from that crusade and the most important commander/leader in that crusade.
The Sixth Crusade started in 1228 as an attempt to regain Jerusalem. It began seven years after the failure of the Fifth Crusade. It involved very little actual fighting. The diplomatic manoeuvring of the Holy Roman Emperor, Frederick II resulted in the Kingdom of Jerusalem regaining control of Jerusalem and other areas for fifteen years. | 
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