Who was Maitreya in Buddhist tradition?

In Buddhist tradition, Maitreya is the future Buddha who currently resides as a bodhisattva in the Tushita heaven. He is expected to descend to Earth to preach the dharma (law) once the teachings of Gautama Buddha have completely decayed.1

Key aspects of Maitreya include:

• Significance: He is the earliest bodhisattva around whom a cult developed, with mentions in scriptures dating back to the 3rd century CE. He is accepted by all schools of Buddhism and remains the only bodhisattva generally honored by the Theravada tradition.1
• Eschatological Role: Maitreya is a central figure in Buddhist eschatological and millenarian thought. It is believed he will preside over a kingdom of peace and enlightenment. In some traditions, particularly in China, beliefs surrounding his imminent arrival have historically influenced the formation of movements challenging established political orders.2
• Etymology and Representation: His name is derived from the Sanskrit maitrī ("friendliness"). He is depicted in art as both a bodhisattva and a buddha, often shown seated in a European fashion or with ankles loosely crossed, conveying an air of expectancy.1