にて

Etymology
Supposed as case particle + conjunctive particle. Compare.

An alternative analysis suggests that may be a conjugation of an ancient copular or stative verb, which persists in modern Japanese as particle  and auxiliary verb  /. This would make nite appear to be a regular conjunctive conjugation of the copula. Compare the て form of Japanese verbs.

Particle

 * 1) formal version of, indicating location or instrumental