At which stage of a case proceeding does a court acquire in personam jurisdiction over a defendant?

Before the legal proceeding began.

Explanation:

In personam jurisdiction is the authority that the courts have to determine the personal rights and liabilities of the parties before the proceedings began. If this jurisdiction lacked from the court which attends the case then it wouldn´t have the authority to bind the defendant to an obligation or adjudicate rights over a property.

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