Who first enjoined Sunday-keeping by law?

Answer

Constantine the Great.
NOTES - "The earliest recognition of the observance of Sunday as a legal duty is a constitution of
Constantine in AD. 321, enacting that all courts of justice, inhabitants of towns, and workshops were to be
at rest on Sunday (venerabili die Solis), with an exception in favor of those engaged in agricultural labor. "Encyclopedia Britannica, ninth edition, article "Sunday."
"Constantine the Great made a law for the whole empire (AD. 321) that Sunday should be kept as
a day of rest in all cities and towns; but he allowed the country people to follow their work."-Encyclopedia
Americana, article "Sabbath."
"Unquestionably the first law, either ecclesiastical or civil, by which the Sabbatical observance of
that day is known to have been ordained, is the edict of Constantine, AD. 321."-Chambers' Encyclopedia,
article "Sabbath."

What was one direct purpose of the incarnation of Christ?
What command did the Lord later give to Abraham?
In what promise was a Saviour from sin first revealed?
How was the overthrow of ancient Babylon foretold?
How many will see Him when He comes?
Why was the gospel to be preached to the Gentiles?
To whom did Jesus first send the twelve disciples?

Questions & Answers are from the book Bible Readings for the Home Circle