The other important group of friars was started by Dominic de Guzman (1170-1221), from Spain. His reason for starting an order of friars was that he saw a connection between the lack of education among a basically ignorant clergy, and heresy.
At their worst, the Dominicans were the "watch-dogs of the Lord", those who rooted out heresy. At their best, they were the learned ones of their day. Where Francis didn't want his friars to even have a breviary, Dominic wanted his to have books, and in fact made it mandatory. The Dominicans soon became the academics -- University of Paris, for example, had many Dominicans on faculty.
Important Dominicans: Albertus Magnus; St. Thomas Aquinas; Meister Eckhart; Catherine of Siena; Johannes Tauler; Henry Suso
Relevance to Mysticism: Many Dominicans were interested in the speculative nature of the universe. Theirs was not the love mysticism of the Franciscans, but rather learned speculation on the nature of things. Having said that, Eckhart, Tauler and Suso were still urban preachers, and interested in the spiritual life of the people. So, their writings are still focussed on the nature of the spiritual ascent. They just don't have the same preoccupation as love mystics do, with describing the emotional nature of the experience, the way in which drawing near to God is like marriage.