Expert: J.M.J. West - 2/4/2008

Question
what are the eastern coptic churches and the coptic jacobites?what is there difference historically and ideologiclly?

Answer
I'll take a stab at this, though it is a finer technical point.

The Coptic Churches are a branch of the Christian Church which semi-split from the Main Catholic [or "catholic", if you prefer] church - which was comprised at the time of both the "Roman Catholic" and "Eastern Orthodox" portions of the Church - in the middle of the 5th century over theological issues related to the nature of Christ.

The Coptic Churches are mainly in Egypt, and are believed to have been started by St. Mark, the evangelist that penned the eponymous Gospel.

I am not for certain what or who the "Coptic Jacobites" are.  Syriac Orthodox Church (formerly known as the "Assyrian Orthodox Church") might be what you mean; it was established by St. Peter at Antioch, and they actually keep to an interesting interpretation of Petrine Primacy.

So far as I can tell, the latter group are rather traditional in their theology; the former diverges at the nature(s) of Christ.  Whereas Christianity taught that Christ is One person with Two natures (fully human and fully divine), the Coptic Churches when they split seemed to take a more "monophysitic" (i.e. "of one nature") approach, which was viewed commonly in the early centuries of the Church as a grave heresy.  

Many of the Coptic Churches have since been reconciled to Rome, or have embraced a form of Eastern Orthodoxy.

Does that help?

Pax Christi,

-Justin