The first olympic games took place in the century bce. 6th 2nd 4th 8th 10th

The Answer is "8th century BCE".
Olympic Games were held in honor of "Zeus" a famous mythological god in ancient Greece. 
First modern day Olympics were held in 1896 in Athens, these games gathered 280 participants from 13 nations, there were a total of 43 events competed that year. 

dirty, contaminated water

contaminated food,

chlostrophobic living spaces,

mice infestation,

etc,

the roman army grew in size and became dominant in the mediterranean region.