Military cover written "Κων/πολις 4 Μαιου 1920" from "Θωρηκτόν Κιλκίς". Cachet "ΘΩΡΗΚΤΟΝ ΚΙΛΚΙΣ ΤΑΧΥΔΡΟΜΕΙΟΝ", arr. "ΧΙΟΣ*21.ΜΑΙ.20". Important historical document, between 1920-22 Constantinople was under administration of allied forces. In addition battleship "Κιλκις" participated to the landing og the Greek troops in Smyrna in May 1919...