Shadowmarch had a long history before appearing in print.
Originally, Tad Williams pitched Shadowmarch as a fantasy movie and later a fantasy TV series described as “Hill Street Blues meets Babylon 5 meets Lord of the Rings.” When these early concepts did not find a home, Shadowmarch was reborn as an online serial novel — one of very few such projects anywhere at that time. Released between June 2001 and August 2002 in bi-weekly episodes on Tad’s website, it was an ambitious exploration of what online publishing done right might mean.
The serial format gave Tad the freedom to tell his story in an organic, evolving way improvising and spinning the tale from week to week. This unusual approach allowed him to respond to immediate feedback from readers, and much of that feedback influenced the story itself.
Despite the vibrant community that gathered around the Shadowmarch project, the number of subscribers willing to pay the one-time $14.99 fee to read beyond the initial five free chapters were not enough to make the serial approach viable. After the first year, Tad brought Shadowmarch to a close, and the online project ended.
Tad returned to traditional publishing to finish the Shadowmarch series. The print version of Shadowmarch Volume 1 contains new chapters which were not published in the online serial version, and the story was substantially revised and edited for book publication (notably being rewritten completely in past tense, since the online project used present tense to “give it a sense of immediacy”). Shadowmarch was published in 2004.