Emperor constain influenced the traditions of westers civilizations by -

sending roman soldiers to the middle east

leagalizing christianity wihin the roman empire

codifying roman law in the middle east

unifying europe by founding the holy empire

Please note that there is a mixed reference in your question. The correct name should be Emperor Constantine, not Constain.

Emperor Constantine indeed had a significant influence on Western civilizations. Here are the correct statements:

1. Legalizing Christianity within the Roman Empire: Constantine's Edict of Milan in 313 CE ended the persecution of Christians and granted them religious freedom. This decision played a crucial role in the spread and establishment of Christianity as a major religion in the Western world.

2. Codifying Roman law in the Middle East: Constantine initiated the process of codifying Roman laws, known as the Corpus Juris Civilis or the Justinian Code. The codification of Roman law preserved and systematized legal principles that later influenced legal systems in Europe and beyond, shaping the development of Western legal traditions.

3. Unifying Europe by founding the Holy Roman Empire: Although Constantine did not directly found the Holy Roman Empire, he did establish the Byzantine Empire, which succeeded the Roman Empire in the East. The Holy Roman Empire, founded in 800 CE by Charlemagne, was partially inspired by Constantine's efforts to unify Western Europe under one ruler, adopting elements of Roman governance and Christian influence.

Sending Roman soldiers to the Middle East is not directly attributed to Emperor Constantine. However, he did engage in military campaigns and conflict during his reign, including against the Persians and other neighboring states. These military activities may have had some influence on the Middle East but are not as significant in terms of his impact on Western civilizations as the other listed actions.