STEEL SEAL were born in Rome, Italy, in 2003 as a result of the efforts of the guitar player and songwriter Marco Valerio Zangani, former axeman of the local hard rock group Sacer Tiber. Ho got in touch with some more veterans of the Roman Hard and Heavy scene (the vocalist Bruno Baudo, the bass player Roberto Fasciani and the keyboardist Adriano Rossi, from the Y.J. Malmsteen's cover band Black Stars) and got them togheter around a new project aimed at arranging original songs to submit to the public and to the record companies.

With that line-up STEEL SEAL recorded their Demo 2003, a 5-tracks promo CD with computer synthesized drumming that gained the attention of several record companies during 2004 and led the band to a contract with the Italian label Underground Symphony (producer of Labyrinth, Skylark, White Skull, Shadows of Steel and more well-known metal bands) for the recording of their debut album By The Power Of Thunder. Shortly after some problems with the line-up led to the giving up of Baudo and Fasciani, while Rossi contributed to the recordings of the album as an additional musician. The bass player and the keyboardist were replaced by Andrea Orciuolo, from the local clubs circuit, and Fabio Bernardi, from the Roman group River of Change; from River of Change came also the new drummer Luca Iovieno (Scapegoat, Enemynside, Dunwich).

About the vocal parts, both the band and Underground Symphony were sure that the quality of the songs could justify the cooperation of a well known international vocalist, so they submitted STEAL SEAL’s promo CD to some of the worldwide top metal singers and gained the willingness to take part in the recordings from renowned singers among which D.C. Cooper (Royal Hunt, Silent Force), who was the final choice for the debut album. During 2006 Steel Seal and D.C. Cooper completed the recordings of the ten songs included in the album and By The Power Of Thunder was released in Japan in December 2006 under licence, by the Label Marquee/Avalon and in the rest of the world during 2007.

In 2008, while the tracks for the second album, entitled Redemption Denied, were taking shape, new problems with the line-up led to the defection of Orciuolo and Bernardi and to the consequent comeback of Fasciani and Rossi. As already happened with the latter for By The Power Of Thunder, also Bernardi contributed to the recordings of the new album as an additional musician, togheter with Lorenzo Milone, a talented guitarist with several experiences with Italian bands, and Marco Ronci, from the Roman band Entròpia. The vocal parts were this time committed to another worldwide well-known metal singer, Thomas Vikström (Candlemass, Brazen Abbot, Stormwind, Therion, ecc.), who recorded them in Argentina in January 2009; on one song Vikström has a duet with the Italian vocalist Val Shieldon (Sigma, Oracle Sun), also credited for the backing vocals in many tracks.

The recordings of the new album finished in the second part of 2009 and Redemption Denied was released worldwide by Underground Symphony in 2010. The eleven songs included in the album derive from the mix of hard rock with neoclassical power metal so typical of STEEL SEAL music, tought out to merge power and melody, harmony and aggressiveness. As usual since the first album, special efforts were made in order to get high quality lyrics that could rely on meaningful and intense verse, often inspired by rhymes of classic British and American poets.

In 2011, with a finally settled line-up, the band started to work at the following album, whose making, however, turned out to be long and troubled, owing specially to the problems in finding a vocalist able to make the most of an already first-class tracklist. In the end, they came to an agreement with the well-known Italian singer Fabio Lione (Labyrinth, Rhapsody of Fire, Vision Divine, Angra), who recorded the vocal parts of the ten songs in the album as a special guest, and after further delays due to management considerations of their Label, The Lion's Den was released worldwide by Underground Symphony in 2017. Besides Lione, other guests are Lorenzo Milone, as for the previous album, and the keyboardist Andrea De Paoli (Shadows of Steel, Labyrinth, Vision Divine).

The album enhances to the highest degree the neoclassical influences of the band (Bach, Vivaldi, Verdi), interpolating in some songs entire passages of famous pieces (Beethoven, Paganini, Albinoni) and blending them perfectly in the framework. The final result was very well received by the critics, the experts in the field and the metal fans, even better than the already warm welcome given to the previous two albums: the excellent reviews and the high-ranking evaluations and marks assigned to The Lion's Den by metal magazines, fanzines, web sites and forums, ecc., are evidence of it.

Subsequently STEEL SEAL, with the same musicians (Zangani, Rossi, Fasciani and Iovieno), including Lione as a session vocalist again and Milone as a guest as usual, recorded, from 2018, the still unreleased new album Fireraiser: the master was completed in 2020 at the Outer Sound Studios in Rome, like its three predecessors. On one song, Lione sings a duet with Italian vocalist Andrea Marchisio (Desdemona, Highlord); another guest is Val Shieldon again (now with Twilight Zone), who sings a cover of Lost and Lonely Days by Warlord. The release of the album is about to be scheduled by Underground Symphony.