This volume presents the first edition of the Letters of Iakovos Monachos addressed to the sevastokratorissa Eirene, sister-in-law of the Emperor Manuel I Komnenos (1143-1180). Writing in the late 1140s, Iakovos offers spiritual advice to Eirene, and affirms his support for her in times of trouble. This is a rare example of the correspondence of a Byzantine spiritual father and provides tantalizing glimpses into Eirene's difficult life. Both are significant figures in Byzantine cultural history, Iakovos as the author of the renowned Kokkinobaphos Homilies on the Theotokos and Eirene as a noted literary patroness. The Letters' style is striking. They are constructed almost entirely from a mosaic of quotations from the Cappadocian Fathers and other patristic authors, the most recent being Niketas of Herakleia. Very little can be attributed to the pen of Iakovos himself, leaving questions about his motivation but also incidental insights into the holdings of a monastic library. The Letters are preserved in a handsome contemporary manuscript, very probably a presentation copy made for Eirene or her heirs, and two fragmentary late sixteenth-century copies. The edition is accompanied by the usual apparatuses and indices, and a full introduction discussing the transmission of the text and setting out the context for Eirene's life and the correspondence. The book will be of interest to specialists in Byzantine spirituality, Byzantine epistolography, the history of the twelfth century, women's history, and Byzantine literacy. Languages: Greek, English.