Answer:

LIII

Answer	Crossword Clue
LIII	53
LIII	X into DXXX
LIII	DXXX - X

LIII	20% of CCLXV
LIII	Ovid's 53
LIII	Caesar's 53
LIII	10% of DXXX
LIII	First-century date
LIII	53, in Roman numerals
LIII	Half of CVI
LIII	One-fifth of CCLXV

LIII	53, in old Rome
LIII	One-eighth of CDXXIV
LIII	Two-thirds of 10% of DCCXCV
LIII	Fifty-three.
LIII	53.
LIII	Year in reign of Claudius I.
LIII	1st-cen. date.
LIII	Year of Nero's first marriage.

LIII	Year in reign of Claudius I
LIII	Roman 53
LIII	Year in the reign of Claudius I
LIII	Pliny's 30th year
LIII	Year in Claudius I's reign
LIII	Pompey's 53
LIII	CLIX trisected
LIII	Next-to-last year in Claudius's reign

LIII	Year B.C. in which Crassus died
LIII	CVI halved
LIII	Year Trajan was born
LIII	Chapter 53
LIII	Nero's 53
LIII	Year in the reign of Claudius
LIII	53, to Ovid
LIII	10 percent of DXXX

LIII	Early Roman date
LIII	53 to Pompey
LIII	XXXVII+XVI
LIII	Super Bowl that will be held in 2019