The expression implies, at least, four or five monarchs; and thus we have no choice but to suppose that the succession of the kings is here imperfect, and that at least one or two reigns were interposed between those of the second Mithridates and of the monarch known as Sanatroeces, Sinatroces, or Sintricus.
A casual notice of a Parthian monarch in a late writer may supply the gap, either wholly or in part.

Lucian speaks of a certain Mnasciras as a Parthian king, who died at the advanced age of ninety-six.

As there is no other place in the Parthian history at which the succession is doubtful, and as no such name as Mnascris occurs elsewhere in the list, it seems necessary, unless we reject Lucian's authority altogether, to insert this monarch here.

We cannot say, however, how long he reigned, or ascribe to him any particular actions; nor can we say definitely what king he either succeeded or preceded.

It is possible that his reign covered the entire interval between Mithridates II.