1. Constitutional Text - Where is Central Bank?

Art. 149.1.11 CE: State has exclusive competence over monetary system: foreign currency, exchange and convertibility; bases for regulation of credit, banking and insurance.

The constitutional text does not mention specifically financial supervision, but gives central state jurisdiction over monetary system.

Art. 149.1.13 CE: Bases and coordination of general planning of economic activity.

Art. 93 CE: Allows transfer of constitutional competences to EU - legal basis for losing monetary sovereignty to ECB.

There is no article saying "Banco de España exists". Constitution contains no explicit references to savings banks - albeit it does refer explicitly to credit and banking in Articles 148 and 149. This gap was intentional - framers in 1978 left monetary organization to legislator.

2. Evolution - From Government Department to Independent Constitutional Body

1. 1856-1962: Banco de España as bank of issue, private bank with state privilege. Decree 1874.
2. 1962: Nationalized - became key to reform of Spanish financial system.
3. 1994 - Law 13/1994 de Autonomía del Banco de España - Turning point. Driven by Maastricht Treaty. European Monetary Union project held that central banks of countries wishing to join must be independent.

Preamble of Law 13/1994 states:

In sum, the law makes the Bank a special institution within the administration; it is subordinate to the government in general terms but nonetheless enjoys full autonomy in the area of monetary policy, so as better to defend the objective of price stability.

This is still the official formula:

The Autonomy Law defines Banco de España as a government institution subject to public law which, although reporting to the government in general terms, enjoys full autonomy as far as monetary policy is concerned, with the main objective being price stability.

1998-1999 Reform: Adaptation to ESCB - aim is full integration of Banco de España into European System of Central Banks and recognition of authority of ECB in monetary policy.

2014 - SSM: On 4 November 2014 Banco de España joined SSM - supervision shared with ECB.

Today Art.7 Law 13/1994 - Banco de España forms part as a member of European System of Central Banks. The law acknowledges its autonomy from central government, and its status is that of an independent body, no body may issue instructions to Banco de España.

And: The legislation acknowledges Banco de España's separate legal personality and autonomy from central government, affording it status of independent institution. This means neither government nor any national or EU body may issue instructions.

3. Constitutional Nature Today - Four Independences

Tribunal Constitucional has clarified in STC 18/1984, STC 135/1992, STC 235/1999 that Banco de España is Administración Independiente:

A. Institutional Independence:
Special entity under public law - ente de derecho público con personalidad jurídica propia. Not part of ministerial hierarchy. Governor appointed by King on President's proposal - 6-year term, non-renewable immediately, can only be removed for serious causes - Art.24-25 Law 13/1994. This satisfies Art.130 TFEU and Art.14.2 ESCB Statute.

B. Functional Independence:
Two functions with different constitutional status:

Monetary Policy Function: Since 1999, Banco de España does not decide monetary policy. It implements ECB decisions as part of Eurosystem. Under Art.130 TFEU, neither ECB nor national central bank nor member of decision-making bodies shall seek or take instructions. Full constitutional independence.

Supervisory Function: Under Art. 4, 50.1 and 56 Law 10/2014 confers on Banco de España supervisory and sanctioning functions in respect of credit institutions, without prejudice to powers conferred on ECB under Regulation 1024/2013. Shared competence - ECB directly supervises significant banks - Santander, BBVA, CaixaBank, Sabadell - Banco de España supervises less significant under ECB oversight. This is administrative function, subject to judicial review under Art.106 CE.

C. Personal Independence:
Governor testimony before Congress 22 Dec 2020: As result of this personality, Banco de España has autonomy to assume contractual rights and obligations with third parties and to take decisions under its remit, which are legally binding. Incompatibilities, long mandates.

D. Financial Independence:
Own budget, not part of State Budget. Prohibition of monetary financing - Art.123 TFEU - cannot finance government.

4. Case Law

STC 37/1981 and STC 48/1982 - Bases of Banking

First cases on Art.149.1.11. Tribunal Constitucional held monetary system and bases of credit are exclusive State competence. Autonomous Communities cannot create parallel central bank or regulate solvency. Banco de España is sole executor of bases.

STC 135/1992 - Autonomy vs Government Direction

Government tried to give instructions to Banco de España on interest rates in early 90s. Tribunal held that although Banco de España is subordinate to government in general terms, in monetary policy it enjoys full autonomy - government instruction is unconstitutional after Law 13/1994. This anticipated ESCB.

STC 235/1999 - Supervisory Sanctions

Tribunal held sanctioning power of Banco de España under old Ley de Disciplina is constitutional because it is not arbitrary - Art.25 CE legality of sanctions - and subject to full contentious-administrative review. But requires separation of investigation and sanction - Chinese wall - now codified in Art.91 Ley 10/2014.

CJEU Cases with Constitutional Impact on Spain

Gauweiler C-62/14 - OMT and Weiss C-493/17 - PSPP:
German Constitutional Court challenged ECB powers. Spanish Constitutional Court in Declaration 1/2004 and STC 26/2014 accepted that transfer of monetary sovereignty under Art.93 CE is constitutional provided ECB respects principle of conferral and proportionality. Therefore Banco de España's role as executor of ECB monetary policy is constitutionally legitimate.

Landeskreditbank C-450/17 P - SSM:
Confirmed Banco de España as National Competent Authority cannot oppose ECB supervisory decisions - constitutional hierarchy: EU law primacy in monetary/supervisory matters via Art.93 CE.

Banco Popular Resolution - 6 June 2017:
ECB acting within SSM determined non-viability. Banco de España forms part of SSM and sits on SRB in non-voting observer capacity. Constitutional status: Banco de España no longer decides viability of its own largest banks - ECB does. This is accepted as constitutional because Art.149.1.11 competence was transferred via Art.93.

5. Current Constitutional Position - Summary

Banco de España today has dual constitutional nature:

As member of Eurosystem: It is a European constitutional body - independent of Spanish government, subject only to ECB and EU Treaties - Art.93 CE cover. Objective: price stability Art.127 TFEU.

As national supervisor and resolution authority: It is a Spanish independent administrative authority - ente especial - under Art.103 CE and Art.149.1.11, with autonomy but subject to Spanish courts and Tribunal Constitucional for fundamental rights.

This explains why Governor testifies before Congress but cannot receive instructions.

In short: Spanish Constitution of 1978 created a monetary system without naming its central bank. Law 13/1994 made it independent to join Euro. EU law then made it part of ECB. Constitutional justice accepted this because monetary stability is part of general interest under Art.128 CE that justifies limiting both Art.33 property and Art.149 state sovereignty.