Conversation so far:
When was the band  Morbid Angel formed?
Morbid Angel was formed in 1983.
Where was the band Morbid Angel started?
Morbid Angel was formed in Tampa, Florida.
Who were the members of the band Morbid Angel?
The founding members of Morbid Angel are guitarist Trey Azagthoth and drummer/vocalist Mike Browning.
What was the name of Morbid Angel's first album?
Altars of Madness is the debut studio album of Florida-based death metal band Morbid Angel.
When did Morbid Angel record their first album?
Altars of Madness was recorded December 1988.
How many copies of their first album did Morbid Angel sell?

Question: When did they release Altars of Madness?
Self-contained rewrite: When did Morbid Angel release Altars of Madness?