Who was Casca loyal to in Julius Caesar?

Casca is loyal to Brutus, Cassius and the other conspirators.

Casca is one of the conspirators from the beginning.  He is clearly no friend of Caesar.  He is the one who stabs Caesar first, at Brutus’s order.

Casca is very sarcastic in his references to Caesar.  He tells Brutus and Cassius about the incident at the Feast of Lupercal when Caesar had his fit.  Antony offered Caesar a crown three times, and he refused.  Casca...

Casca is loyal to Brutus, Cassius and the other conspirators.

Casca is one of the conspirators from the beginning.  He is clearly no friend of Caesar.  He is the one who stabs Caesar first, at Brutus’s order.

Casca is very sarcastic in his references to Caesar.  He tells Brutus and Cassius about the incident at the Feast of Lupercal when Caesar had his fit.  Antony offered Caesar a crown three times, and he refused.  Casca is irritated with the showmanship, and how easily the people fell for it.

Marry, before he fell down, when he perceived the
common herd was glad he refused the crown, he
plucked me ope his doublet and offered them his
throat to cut. (Act 1, Scene 2)

Casca hates Caesar so much he is willing to kill himself rather than be under his rule.  He gladly takes part in the conspiracy to kill Caesar, stabbing him in the throat.  In fact, Casca was a bit of a thug.  Even though he was the first to stab, historians believe his was the fatal blow.  The others stabbed Caesar while he was bleeding out.

CINNA

Casca, you are the first that rears your hand. (Act 3, Scene 1)

Antony is well aware that Casca was the first person to strike Caesar.  He tells Cassius as much during the parley.  In doing so, Casca was one of the ones who was mostly ruthlessly hunted down by Antony’s mob.  He was considered Caesar’s murderer, even though there were many that followed him.

Casca was a true believer.  He hated Caesar, and was clearly more of a follower than a leader.  He did what he was told, when he was told.  He was a superstitious man and worried when he saw signs that might be interpreted as bad omens, yet he stayed true to his course.  Known as a murderer, in his own way he was a patriot.  He believed that Caesar was the worst thing possible for Rome.