Answer: MDL

AnswerCrossword Clue
MDLYear Nostradamus's first almanac was written
MDLCenturies ago.
MDLMiddle of 16th century
MDLYear Helsinki was founded
MDLCaesar's 1550
MDLYear in the reign of Edward VI
MDLYear in the reign of Ivan the Terrible
MDLRoman 1,550
MDLMidcentury year
MDL16th cen. date.
MDLYear of Ronsard's "Odes"
MDLThe year 1550
MDLYear Charles IX was born
MDLNero's 1,550
MDLLivy's 1,550
MDLCato's 1,550
MDLMonumental 1550
MDLMid-16th century date
MDLL x XXXI
MDL1550 in Rome
MDLMid-XVIth century
MDLYear of Pope Julius III's election
MDL16th-century date
MDLCCCX x V
MDL1550, in old Rome
MDL1550, to Flavius
MDLCaesar's 1,550
MDLMid-sixteenth-century date
MDLMiddle of the 16th century
MDLMid-16th century year
MDL1550
MDLCCCX quintupled
MDLHalf of MMMC
MDLNero's 1550
MDLStart of Julius III's papacy
MDLMiddle of the 16th century.