Sphakteria island straddles the mouth of Pylos (Navarino) bay in Messenia, SW Peloponnese, Greece; Barrington Atlas map 58 grid B4. It is especially associated with a campaign of 425/4, when Athenian troops trapped and captured a detachment of their Spartan counterparts (Thucydides 4.1-41). For Sphakteria (and this event) elsewhere in the Suda cf. alpha 4564, epsilon 1061, epsilon 3348, kappa 1731, lambda 272 (which shares the confusion of the present entry: see below), and chi 162.
The present entry derives from the scholia on Aristophanes, Knights 55 (where in fact Pylos rather than Sphakteria itself is mentioned). However, in no sense can Sphakteria be described as preventing invasions of Spartan territory from Thessaly. Rather, there is confusion here with Thermopylai (theta 248, theta 249). Even worse is the notion that a place in Spartan territory could prevent invasions from Spartan territory itself. The nonsense purveyed by the latter parts of the present entry is a late displacement of the material originally found in the scholia. Paradiso [below] now gives a full exposition of the problem as it relates to Leonidas, and traces the dual source tradition which lies behind lambda 272 (Nicolaus) as well as the present entry.
[1] The regular name for Spartan territory; cf. next note.
[2] 'Lakedaimonia' is a post-classical name.
[3] lambda 272. See under primary note above.
[4] The text breaks off here.