There are multiple artists with this name:
1) Altar was a death metal band from The Netherlands.
Band's Info 2) Altar was an early death metal band from Sweden.
Band's Info 3) Altar was a Speed Metal / Thrash Metal band from France.
Band's Info 4) Altar is a Hardcore / Thrash Metal band from Romania.
Band's Info 5) Altar is a deaththrash band from Turkey.
Band's Info 6) Altar was a heavy metal/ power metal band from USA.
Band's Info

Read more about Altar on Last.fm.