Two inscriptions, one (A) found at Tylissos on Crete, the other (B) found at Argos, both dated about 450, concern relations between Argos and the Cretan towns of Knossos and its smaller neighbour, Tylissos. The close relationship between the treaties of fragment A and fragment B – and therefore the interconnection among Argos, Knossos, and Tylissos – seems generally recognized by scholars. The articles of the agreement lay down a diverse and complex set of arrangements among the three parties, but as a whole, the treaty has been interpreted in two ways: (1) the three πóλεις have entered into some sort of federal union; (2) only Argos and Knossos are signatories to the treaty, while Tylissos is a dependency of Argos. The former interpretation has gained wider acceptance than the latter, and if it is correct, just such a federal union would represent a remarkable advance in the development of Greek political institutions. In this paper we shall press a philological point based upon the information we have both from the treaty and from contemporary sources, and in so doing, we shall attempt to show that a federal union is unlikely. We shall then offer our own interpretation of the regulations governing the insular cities with regard to the formation of alliances and the declaration of friends and enemies.