Petros Peloponnesios arrived in Constantinople from his native Tripolis around 1764, a young cantor coming to study under Ioannes Trapezountios, then the leading musical authority at the Great Church, the Patriarchal Cathedral at the heart of the Ecumenical Patriarchate. He rose quickly through its ranks, serving first as second domestikos, one of the working notators who transcribed the chant performed by more senior cantors, and then, from around 1770 until his death in the Constantinople plague of 1778, as lampadarios, leader of the left choir, one of the two most senior chanting positions in the Great Church itself. From 1776 he also taught formally at the New Music School of the Patriarchate, and it was in that teaching role that he compiled the Doxastarion Syntomon, an abridged collection of sticheraric idiomela, chant settings for the church year, meant to give students a manageable working repertoire rather than the far larger full Doxastarion older cantors had trained on.
The collection was never printed during his lifetime. It circulated instead as working material within the Patriarchate's own teaching, copied and taught cantor to cantor, until it finally reached print in 1820, more than four decades after Petros died. That gap between composition and publication is itself telling, a teacher's working notebook, refined through years of actual classroom use inside the Patriarchate, proved durable enough to be worth printing as a standard reference an entire generation after the man who compiled it was gone.