1203

1203 is a natural number that comes after 1202 and before 1204.

In mathematics, its prime factorization is 3 × 401, with 401 prime; therefore 1203 is composite and square-free. It is odd and divisible by 3 (the sum of its digits is 6). In base representations, 1203 equals 10010110011 in binary, 2263 in octal, and 4B3 in hexadecimal; in Roman numerals it is MCCIII.

In calendar use, 1203 CE falls in the High Middle Ages. The period saw the Crusades and various political changes across Europe and the Byzantine world; the Fourth Crusade was active during this era, and the following year led to the sack of Constantinople and the establishment of the Latin Empire.

Alternative uses include its role as an identifier, model number, or catalog entry in modern systems.