Apprenticed by Lem's first student Tresmillia only months after her own ascension to magehood, Currens Sine Cruris ("Running Without Legs") was declared mage in 213. He was the first of Lem's descendants to be named for a riddle taken directly from the Books of Lem, a practice later to become common within the House.
In 232, Sine Cruris left Evasendia with the north-bound diaspora party. He and his sister Sine Alis got along badly with the Manerean and Eleanorean members of the expedition, however, and at the foot of Whinnie Moor, they refused to travel any further north, announcing that they found this spot, a place of ill-repute among the locals, an ideal location for a new covenant. The Eleanoreans and Manereans disagreed, and the two factions of the expedition parted ways late in 232. Sine Cruris and the other Lemmites ascended the moor and founded Covenant Brellyn in the forbidding bog of Glun Orddu in the spring of 233.
No sooner had the covenant been founded than Sine Cruris began quarrelling with Lem's second student, Consilii Exspectans, over matters of doctrine. Consilii, as a student of Lem himself and the senior member of the House on the expedition, believed that he should be recognized by Tresmillia's students as the leader of the group, and when Sine Cruris and Sine Alis refused to respect his authority, he became disaffected. He converted to Circulan doctrine and departed Covenant Brellyn in 235, leaving Sine Cruris the leader of the covenant. Over the next decade, Sine Cruris was to carry on a lively debate with the Circulan Lemmites over interpretation of the Books of Lem.
Sine Cruris' parens Tresmillia had always followed Lem's example in refusing to comment on the House's doctrinal disputes. In 258, however, her decision to retire from the Council at Evasendia to Covenant Brellyn was seen by many as proof that she supported the Brellyn Lemmites' interpretation. The Brellyn Lemmites were thereafter to be viewed as the most legitimate and presitious of the Lemmite factions, and as leader of the covenant, Sine Cruris enjoyed a great deal of prestige within the Order. He attended the First Tribunal as a representative of Covenant Brellyn in 269.
Sine Cruris supported Lem's accusations against Eleanor in 269 and joined with his parens Tresmillia in levelling accusations against the magi of the Covenant at Chalcyphon. Although he sent his descendants out to join Lem and House Savacion in hunting down Eleanoreans, he himself remained seated on the Tribunal through the course of the purge, returning to Covenant Brellyn only after Eleanor's death in 271. He vanished later that year, along with all of his covenant. He had taught two students:
- Quadra Casta, from 215 to 229
- Temerus Trigonum, from 225 to 238
