Paragon Caridin vanished in the eleventh year of the reign of King Valtor, and with the Paragon the entire process for golem manufacture was lost. Expeditions were sent into the Deep Roads to track him, but the darkspawn drove them all back.
Finally, in the second year of the reign of Queen Getha, one hundred and twenty six golems, the entire Legion of Steel, were sent to recover the Paragon.
The Shaper of Golems refused to support any further attempts to find Caridin, and the Paragon was officially declared dead.
The Shaperate never recovered from the loss of an entire legion of golems, and never again allowed an all-golem regiment into the Deep Roads.
-- From Stone Halls of the Dwarves, by Brother Genitivi, Chantry scholar.