Picture: Fr. Andrew Younan of The Seminary of Mar Abba the Great, 1245 Jamacha Rd, El Cajon, CA, USA 92019 · CC BY-SA 3.0 · Wikimedia Commons

Aba I

Patriarch of the Church of the East at Seleucia-Ctesiphon

SaintPre-congregation

Feast: 28 February (not on the universal Roman calendar; kept in the Roman Martyrology or local calendars)

Born

550

Died

552

Beatified

—

not needed: before formal processes

Canonised

By tradition

recognised before formal processes began

Who they were

Aba I (or, with his Syriac honorific, Mar Aba I) or Mar Abba the Great was the Patriarch of the Church of the East at Seleucia-Ctesiphon from 540 to 552. He introduced to the church the anaphoras of Theodore of Mopsuestia and Nestorius beside the more ancient liturgical rite of Addai and Mari. Though his tenure as catholicos saw Christians in the region threatened during the Perso-Roman wars and attempts by both Sassanid Persian and Byzantine rulers to interfere with the governance of the church, his reign is reckoned a period of consolidation, and a synod he held in 544 as (despite excluding the Diocese of Merv) instrumental in unifying and strengthening the church.

Summary from Wikipedia (CC BY-SA 4.0), until this page is written up in full.

The miracles

Limited information available on this saint.

Why that counted as sanctity

Limited information available on this saint.

Connected on this site

Theodore of Mopsuestia Saint
“He introduced to the church the anaphoras of Theodore of Mopsuestia and Nestorius beside the more ancient liturgical rite of Addai and Mari.” — Wikipedia

Sources

Wikidata Q2708661 — dates, feast day and identifiers (CC0)
English Wikipedia — Aba I (CC BY-SA)

Not yet written up in full: no Church source with an account of this person has been found yet. The name, dates and step come from Wikidata and are not yet checked against Church records.