How was julius caesar able to defy the senate, cross the rubicon, and engage in a civil war with his enemies?

Julius Caesar was able to dey the senate, cross the rubicon, and engage in a civil war with his enemies because:

He had amassed a large loyal army.

Explanation:

Julius Caesar was a formidable roman military leader that achieved great acts by pursuing conquest even though sometimes he started unwanted wars. So, after all his victories he had to go back to Rome, but he risked being accused of starting unwanted wars. So, he marched to rubicon with his full army and took power over the senate to proclaim himself leader for life.

that is probably something for you to answer