tetrarchate

tet·rar·chy

 (tĕt′rär′kē, tē′trär′-) also tet·rar·chate (-kāt′, -kĭt)
n. pl. tet·rar·chies also tet·rar·chates
1. The area ruled by a tetrarch.
2.
a. Joint rule by four governors.
b. The four governors so ruling.