Demetrios Koutroubis (1921-83) was a wholly remarkable figure: one of the greatest, but also one of the least well-known Orthodox theologians of the modern era. Variously described as a lay staretz, a monk of the world, and a latter-day Socrates, Koutroubis is a figure who deserves much more attention than he has hitherto been afforded. Humble and self-effacing, he had no official position in either the Church or the academy, wrote relatively little, and had absolutely no interest in his own reputation or any sort of worldly recognition. But he revolutionized theology and Church life in Greece and beyond, sparking a true renaissance of patristic, liturgical, missionary, and monastic endeavour - a renaissance often referred to in Greek circles as the 'theology of the 1960s'. He was a major inspiration behind some of the most prominent theologians, philosophers, bishops, and monastics associated with this movement. One of those he had the greatest impact on, the renowned philosopher and theologian Christos Yannaras, has memorably declared that theology in modern Greece can be divided into the period 'before Koutroubis' and 'after Koutroubis'.