The first "regulator" in history was established in Barcelona in 1401. That year, a bank of exchange and of common and safe deposit was established under the authority of the municipal magistracy, that ended up working as a de facto regulator of commerce and bankers. The Casa de canvi ("house of exchange" in Catalan) was the first entity of this kind in Europe, as the Bank of St. George at Genoa was not established until 1407. In this kind of common bank communities and individuals kept commodities and cash in any currency and credit was given according to the value of each project.
The late 14th century and early 15th century was a time of crisis all around Europe. The plague had killed a big deal of population - Barcelona had 50.000 inhabitants in 1348 and c. 28.000 in 1400. The plague attacked a population that knew nothing of hygiene and sanitary conditions and that could not defend themselves from an unknown virus. The church blamed the Jewish population on grounds that they refused to adhere to the "true faith". Commerce, external and internal, was paralyzed. Thus the bank of exchange was born as a means to boost, regulate, and protect maritime commerce.
The goals of the Taula de canvi were to fund trade initiatives that because of the hardships of the time did not have or could not find funding, and to regulate trade and control bankers that committed fraud or other offences. If such a thing happened, the responsible for the Casa de canvi smashed that banker's money-changing table with a hammer and the offender was taken to justice. It was at that time that the word "bankruptcy" (that literally means, "break a bank" - the word "bank" meant originally "bench", "table") became popular.
Below, Barcelona in the14th century. From George Braun and Frans Hogenberg, Civitates Orbis Terrarum (1572). Source, Viquipèdia.