This chapter addresses the following themes: 1. Terminological Premise. – 2. Forms of State and Forms of Government: Historical Aspects and Development. – 2.1. The Feudal Society. – 2.2. The Absolute State. – 2.3. The Liberal State. – 2.4. The Democratic Pluralistic State. – 2.5. Alternatives to the Democratic Pluralistic State. – 2.5.1. Totalitarian and Authoritarian States. – 2.5.2. The Socialist State. – 3. Unitary, Federal and Regional States. – 3.1. Allocation of legislative power. – 3.2. Allocation of Judicial Power. – 3.3. Representation in the Upper House. – 3.4. Constitutional Amendment Powers. – 3.5. Statutes of Autonomy or Constitutions? – 3.6. No Decentralisation without Taxation? – 4. Forms of Government: a Synchronic Analysis. – 4.1. The Parliamentary Executive. – 4.2. The Presidential Executive. – 4.3. The Directorial Executive. – 4.4. The Semi-presidential Executive.