How to Speak Proto-Indo-European

[Albion]

Just a question: in your opinion, when and where italic and celtic languages separated?

Somewhere between Austria, Hungary and Slovenia IMO. Not sure about the date when the split happened, I'd say around the late Bronze Age in the part of the world.

[Vesuvian Sky]

Ok time to crack knuckles, and get back into discussing PIE culture and language aspects a bit more.

One such aspect is the notion of Divine Twins, a reoccuring theme in IE mythology. While some of the aspects of this reoccuring theme are circumstancial among various IE groups, nonetheless, they do persist and overlap in similarity (though to varying degrees). A short summation of the IE Divine Twins, from Mallory 1997:

Few mythological themes are as consistent or as widespread
among Indo-European groups as that of the Divine Twins.
Likewise few are as characteristically Indo-European. A pair
of lessor gods, the Divine Twins have enjoyed widespread
popularity in myth, legend and folklore from Sri Lanka to
the Isle of Man.
Their prototype is easily reconstructed from extant mythological
sources. They are two youths, twins or brothers, who
frequently bear the epithet 'son' or 'youth'. They are depicted
as supernatural horsemen and their epiphanies are horses. In
their equine form, they are the divine steeds which draw the
solar chariot. Perhaps for this reason, they are often regarded
as offspring of the Indo-European Sky or Sun gods. They share
a consistent relationship with the Sun god and the goddess
or goddesses who represent the dawn, the morning and
evening stars. One of the latter is presented variously as their
consort, Wife, or sister. Her solar associations are .likewise
extensive, her epiphany is frequently a swan, and she is
identified onomastically with roots meaning 'bright', 'white',
and 'shining'.

Here are a list a brief summation of the Divine Twins thoughout the IE speaking world:

in Greek mythology, the Dioscuri

Spoiler!

Castor and Pollux are consistently associated with horses in art and literature. They are widely depicted as helmeted horsemen carrying spears.[20] The Pseudo-Oppian manuscript depicts the brothers hunting, both on horseback and on foot

in Vedic mythology, the Ashvins

Spoiler!

The Ashvins are Vedic gods symbolising the shining of sunrise and sunset, appearing in the sky before the dawn in a golden chariot, bringing treasures to men and averting misfortune and sickness

in Lithuanian mtyhology, the Ašvieniai

Spoiler!

Ašvieniai are represented as pulling carriage of Saulė (the Sun) through the sky and are represented as little horses.

in Norse mythology, Skinfaxi and Hrímfaxi

Spoiler!

the horses of Dagr (day) and Nótt (night). The names Skinfaxi and Hrímfaxi are bahuvrihis, meaning "shining mane" and "rime mane" (or "frost mane"), respectively. Skinfaxi pulled Dagr's chariot across the sky every day and his mane lit up the sky and the earth below.

in Roman Mythology, Romulus and Remus:

Spoiler!

the twin brothers and central characters of Rome's foundation myth

in the Ulster Cycle, the Twins of Macha:

Spoiler!

the two chariot-horses of the hero Cúchulainn in the Ulster Cycle of Irish mythology.

[rashka]

In Slavic mythology, Dazbog

Spoiler!

Dazbog is the sun god, and a kind of chief god, somewhat similar to Zeus or the Dagda. He has horns and a canine head. Dazhbog travels in a chariot across the sky every day like Helios, bringing justice, prosperity and sunshine to the world. He is known as the grandfather of the Russian people. His attendants include two maidens (the morning and evening stars), seven judges (the planets), and seven messengers (the comets). In one myth, he is married to Lada, and the two secure abundance for the world.

Dažbog (Bosnian, Croatian: Dabog, Daždbog; Bulgarian: Даждбог, Polish: Dadźbóg, Russian: Даж(д)ьбог, Serbian Latin: Dajbog or in cyrillic Дајбог (or Дажбог); Ukrainian: Дажбог), alternatively Dazhbog, Dazbog, Dazhdbog, or Dadzbóg, was one of the major gods of Slavic mythology, most likely a solar deity and possibly a cultural hero. He is one of several authentic Slavic gods, mentioned by a number of medieval manuscripts, and one of the few Slavic gods for which evidence of worship can be found in all Slavic nations.