What factors caused Rome to plunge into civil wars and how did they weaken the republic

Land reform in the form of military servicemen receiving land after a 16-year service term, this meant that patricians could have land taken away from them to offer to servicemen, this was the cause of the first civil war, this resulted in a stronger Senate. The second civil war was centred on the popularity of Caeser, who, after winning the support of the public, becomes a controversial figure to the Senate and Pompey, who believe they should rule Rome on their own, the order Ceaser to give up his army and return home, however, he refuses and after he crossed the Rubicon, the civil war began; this resulted in the dictatorship of Caesar, who is later assassinated in his life.