The Battle of 4 May was fought in open sea near Salvador, Bahia, on May 4, 1823, between the Brazilian Navy

Brazilian Navy

The Brazilian Navy is a branch of the Brazilian Armed Forces responsible for conducting naval operations. It is the largest navy in Latin America...

, under the command of a former admiral of the British Royal Navy, Thomas Cochrane

Thomas Cochrane, 10th Earl of Dundonald

Admiral Thomas Cochrane, 10th Earl of Dundonald, 1st Marquess of Maranhão, GCB, ODM , styled Lord Cochrane between 1778 and 1831, was a senior British naval flag officer and radical politician....

, and the Portuguese Navy during the Brazilian War of Independence

Brazilian Declaration of Independence

The Brazilian Independence comprised a series of political events occurred in 1821–1823, most of which involved disputes between Brazil and Portugal regarding the call for independence presented by the Brazilian Kingdom...

.

Ships involved:

Brazil (Cochrane)

Names of the ships involved followed by the amount of cannons that ship had (when the amount is known):

• Pedro I 64 (flag, captain Crosbie)
• Maria da Glória (Beaurepaire)
• Piranga (Jowett)
• Liberal (Garcão)
• Guarani
• Real
• Nitheroy (Taylor)

Portugal

Names of the ships involved followed by the amount of cannons that ship had (when the amount is known):

• Dom João 74
• Constituição 50
• Pérola 44
• Princesa Real 28
• Calypso 22
• Regeneração 26
• Activa 22
• Doze de Fevereiro 26
• Audaz 20
• São Gualter 20
• Príncipe do Brazil 26
• Restauração 26
• Conceição 8