CORRECTIONS of the earlier post:
Indeed, the Maronites are a Catholic particular church without an obvious non-Catholic counterpart that was historically united with it. Note that they do not use the word “Catholic” in the official name of the church. Here’s a table of the 23 particular Catholic churches and their corresponding churches grouped by liturgy (C = Church, CC = Catholic Church, OC = Orthodox Church, EO = Eastern Orthodox, OO = Oriental or non-Chalcedonian Orthodox, so-called “Monophysite”, StTC = St. Thomas Christians):
Alexandrian liturgy:
Coptic CC : Coptic OC (OO)
Ethiopian CC : Ethiopian Orthodox Tewahedo C (OO), Eritrean Orthodox Tewahedo C (OO)
Antiochian (West Syriac) liturgy:
Maronite C : (none)
Syriac CC : Syriac OC -](EO)/-] (OO)
Syro-Malankara CC (StTC) : Malankara Orthodox Syrian C (OO, StTC); Malankara Syriac Orthodox Church (so-called Syrian Jacobite Church in India)
Armenian liturgy:
Armenian CC : Armenian Apostolic C (OO)
Chaldean (East Syriac) liturgy:
Chaldean CC : Assyrian C of the East (not EO or OO, so-called “Nestorian”)
Syro-Malabar CC (StTC) : -]Malankara Orthodox Syrian C (EO, StTC), Jacobite Syrian Christian C (EO, part of the Syriac OC)/-] Assyrian C of the East (Called Chaldean-Syrian Church in India, based in Trichur)
Byzantine liturgy:
Albanian Byzantine CC : Albanian OC (EO)
Belarusian Greek CC : Belarusian OC (EO, part of Russian OC)
Bulgarian Greek CC : Bulgarian OC (EO patriarchate)
Byzantine C of Croatia, Serbia, and Montenegro : Serbian OC (EO patriarchate)
Greek Byzantine CC : C of Greece (EO)
Hungarian Greek CC : (none; essentially all EO Christians in Hungary are non-Hungarians)
Italo-Albanian (Greek) CC : (none)
Macedonian Byzantine CC : Macedonian OC (EO, but technically in schism from Constantinople)
Melkite Greek CC : Greek OC of Antioch (EO patriarchate)
Romanian C United with Rome : Romanian OC (EO patriarchate)
Russian Greek CC : Russian OC (EO patriarchate)
Ruthenian CC : -](none, the CC mostly exists in the US)/-] ACROD, OCA (EO)
Slovak Greek CC : OC of the Czech Lands and Slovakia (EO)
Ukrainian Greek CC : Ukrainian Autocephalous OC (EO), Ukrainian OC Moscow Patriarchate (EO, part of Russian OC), Ukrainian OC Kyiv Patriarchate (in schism from Constantinople), UOAC (in schism from Constantinople)
Roman liturgy:
Latin C : (none, but there are various Western Orthodox individual churches, some in communion with Constantinople, some not)
The result of this mess is that there are five patriarchs of Antioch (-]Assyrian/-], EO patriarchate, OO Patriarchate, Maronite, Melkite, Syrian CC) and four of Alexandria and All Africa (Coptic OC, Coptic CC, EO patriarchate, Melkite). There were formerly Latin Patriarchs too, but they have been abolished.