♠Mercenarios♠ was formed in Barcelona, in July 2000, by the singer Carlos Esteras after the dissolution of the band Escalera de Color.

At the beginning it wasn’t easy, some musicians formed part of the band but they stayed for short time. For that reason the vocalist Carlos decided only compose. In mid 2007 Carlos ran into good friends, the guitarist Marc Martorell (ex-Transylvania) and the bass player Lukhas Komunyas (ex-Achtung) in a concert. It was there when Carlos proposed them to work together on the Mercenarios project. Carlos had already composed enough songs. Marc and Lucas already knew the musical work of Carlos, so they accepted. In order to complete the band they invited Tony Metal (ex-Motosierras) who joined the band as a drummer and producer. In October 2007 the band recorded the first album in Black Rhino studios.

At the end of March 2008 the project was released with an album full of rock and roll, fast, hard and powerful called ♠Mercenarios♠.

After Lucas left the band and Manu Reno (ex-Voll Band), an old friend mate of the singer, replaced him. They toured introducing the album. The highlighted tracks were "Rock y Dios", the ballad "Mientras dormías" and the hit single "Mercenarios". This track had a videoclip. But in a short time the band broke.

After a period of time, Carlos Esteras got in touch with Marc Martorell again, they decided to look for musicians. In 2014 the band was created again. The new musicians were: the bass player José Templado (ex-Sergeant Rock) and the drummer Robert Cat (ex-Irthangaz).

The results of the band weren’t as they expected and the band broke again, Carlos decided to renew the band.

At the end 2017 the band was formed again with José Tavero as a lead guitar (ex-Blackouters and ex-Lost Oxymoron), Ivan Tenaz (ex-Soulless) as a drummer and Oscar Krasher as a bass player, the last one a four string virtuous who completed the line-up.

In 2018 they made some concerts introducing the new band and in January 2019 they recorded a new album full of pure rock and roll metal and rider theme, called "Barcelona R&R".

At the end of 2019 Oscar Krasher leaves the band and is replaced by Javier Barrecha (ex-Manzano), with the new complete lineout they begin to compose new material for the next album. At the beginning of 2020, with the arrival of the global pandemic, they present the new formation through their social networks, in 2021 they publish their third studio work entitled "Días de Pandemia".