Historical Context:
* The crusades were a series of religious wars fought between European Christians and Muslims in the Middle Ages.
* The Knights Templar were a powerful military order that participated in the crusades.
Modern Usage (Figurative):
* The environmental activist launched a crusade to save endangered species.
* The politician is on a crusade against corruption in government.
* She has been on a crusade to improve literacy rates in her community.
Informal Usage:
* My mom is on a crusade to get me to eat more vegetables.
* My friend is on a crusade to find the perfect cup of coffee.
Important Note: The word "crusade" often carries a strong connotation of moral righteousness and unwavering commitment, even if the cause itself is controversial. It's important to be aware of this when using the word.