Sovereign immunity, or crown immunity, is a type of immunity that in common law jurisdictions traces its origins from early English law. Generally speaking it is the doctrine that the sovereign or government cannot commit a legal wrong and is immune from civil suit or criminal prosecution; hence the saying, the king (or queen) can do no wrong. In many cases, the government has waived this immunity to allow for suits; in some cases, an individual, such as an attorney general, may technically appear as defendant on the government's behalf.

In constitutional monarchies

Subject-matter jurisdiction:
Personal jurisdiction: Federal sovereign immunity
In Hans v. Louisiana, the Supreme Court of the United States held that the Eleventh Amendment re-affirms that states posses sovereign immunity and are therefore immune from being sued in federal court without their consent. In later cases, the Supreme Court has strengthened state sovereign immunity considerably. In Blatchford v. Native Village of Noatak, the court explained that
we have understood the Eleventh Amendment to stand not so much for what it says, but for the presupposition of our constitutional structure which it confirms: that the States entered the federal system with their sovereignty intact; that the judicial authority in Article III is limited by this sovereignty, and that a State will therefore not be subject to suit in federal court unless it has consented to suit, either expressly or in the "plan of the convention."
(Citations omitted). In Alden v. Maine, the Court explained that while it has
sometimes referred to the States' immunity from suit as "Eleventh Amendment immunity[,]" [that] phrase is [a] convenient shorthand but something of a misnomer, [because] the sovereign immunity of the States neither derives from nor is limited by the terms of the Eleventh Amendment. Rather, as the Constitution's structure, and its history, and the authoritative interpretations by this Court make clear, the States' immunity from suit is a fundamental aspect of the sovereignty which the States enjoyed before the ratification of the Constitution, and which they retain today (either literally or by virtue of their admission into the Union upon an equal footing with the other States) except as altered by the plan of the Convention or certain constitutional Amendments.
Writing for the court in Alden, Justice Anthony Kennedy argued that in view of this, and given the limited nature of congressional power delegated by the original unamended Constitution, the court could not "conclude that the specific Article I powers delegated to Congress necessarily include, by virtue of the Necessary and Proper Clause or otherwise, the incidental authority to subject the States to private suits as a means of achieving objectives otherwise within the scope of the enumerated powers."
However, a "consequence of [the] Court's recognition of pre-ratification sovereignty as the source of immunity from suit is that only States and arms of the State possess immunity from suits authorized by federal law." Northern Ins. Co. of N. Y. v. Chatham County (emphases added). Thus, cities and municipalities lack sovereign immunity, Jinks v. Richland County, and counties are not generally considered to have sovereign immunity, even when they "exercise a 'slice of state power." Lake Country Estates, Inc. v. Tahoe Regional Planning Agency.

Exceptions and abrogation
Michael J. Kelly, Nowhere to Hide: Defeat of the Sovereign Immunity Defense for Crimes of Genocide & The Trials of Slobodan Milosevic and Saddam Hussein (Peter Lang 2005).