<P> On 7 March 321 , Constantine I , Rome 's first Christian Emperor ( see Constantine I and Christianity ) , decreed that Sunday would be observed as the Roman day of rest : </P>
<P> On 7 March 321 , Constantine I , Rome 's first Christian Emperor ( see Constantine I and Christianity ) , decreed that Sunday would be observed as the Roman day of rest : </P>
who declared sunday as holiday for the first time in the world
who declared sunday as holiday for the first time in the world
Constantine I , Rome 's first Christian Emperor
Constantine I , Rome 's first Christian Emperor