Decadarchia
or
Decarchia (
δεκαδαρχία, δεκαρχία).
A council or government of ten.
1.
In Thessaly, established by Philip on his conquest of that country and the overthrow of its
tyrants in B.C. 352, after a defeat in the previous year (Demosth.
Phil. ii. p. 71.22).
2.
Introduced by Lysander at the close of the Peloponnesian War, and established in many Greek
cities by the Lacedaemonians, who intrusted to it the whole government of the State under the
direction of a Spartan harmost. It always consisted of the leading members of the
aristocratic party (
Xen. Hell. vi. 3.8). The
form
δεκαδαρχία is used by Demosthenes of the Thessalian
institution, and
δεκαρχία by Xenophon and Isocrates of the
Lacedaemonian.