Opinion of ROBERTS, C. J.
States did not “ ‘surrender . . . this immunity in the plan of the convention.’ ” Id., at 717 (quoting The Federalist No. 81, p. 487 (C. Rossiter ed. 1961) (A. Hamilton)); see also Alden, supra, at 718–722, 755–756. There is no reason to suppose that the States, at the founding, made an exception for private suits that happen to mimic other plaintiffs’ claims—and neither Arizona nor the Court today suggests otherwise.
Whether or not a plaintiff “seeks the same relief” or imposes any “additional defense or liability,” ante, at 23–24, simply does not matter in light of our recognition that sovereign immunity provides an “immunity from suit,” not a “defense to . . . liability.” Federal Maritime Comm’n v. South Carolina Ports Authority, 535 U. S. 743, 766 (2002). As we have explained, “the relief sought by a plaintiff suing a State is irrelevant to the question whether the suit is barred.” Seminole Tribe of Fla. v. Florida, 517 U. S. 44, 58 (1996). Indeed, we have suggested that private parties may not sue even if a court is “precluded . . . from awarding them any relief.” Federal Maritime Comm’n, supra, at 766 (emphasis added) (dictum). It is the fact that a private party is allowed to sue a sovereign State—not the burden of litigation or the relief sought—that infringes the immunity of the State. “The Eleventh Amendment is concerned not only with the States’ ability to withstand suit, but with their privilege not to be sued.” Puerto Rico Aqueduct and Sewer Authority v. Metcalf & Eddy, Inc., 506 U. S. 139, 147, n. 5 (1993).
It is therefore impossible for the Court to hear private claims against a nonconsenting State without expanding “our judicial power over the controversy.” Arizona, supra, at 614. Sovereign immunity is a limitation on that power. The similarity of claims may be relevant to joinder or intervention, but those are procedural means of processing claims, not fonts of judicial authority. See Henderson v. United States, 517 U. S. 654, 664 (1996).
