The book is an annotated critical edition of an unpublished collection of hymnographical texts, preserved in the 11th-12th-century Greek manuscript 11 of the library of Leimonos Monastery, Lesbos, Greece. This important codex is a Menaion for the month of June, comprising thirty akolouthiai on saints; twenty of them hitherto unpublished. The edition of the texts is accompanied by an introduction, a commentary, appendices of unpublished hymns preserved in manuscripts other than Lesbiacus Leimonos 11, a full bibliography, indices and plates with facsimiles of selected folios of manuscripts.