Coenus of Macecon

Coenus or Koinos was, according to Eusebius of Caesarea, the second king of Macedonia after Carano. 

The Greek historian Marsyas of Pella, Macedonia, tells the following causal story about his name: 
"...a certain Knopis from Colchis came to Macedonia and lived in the court of Caranos; when the royal male child, Caranos, was born. he wished to give him the name of his father, Kyraron or Kararon, but the mother objected and wanted to name the child when asked Knopis gave the answer: by no name, therefore he was called Koinos (common)".

According to Eusebius, he reigned for twelve years and was succeeded by his son Tyrimmas.

However, this position is disputed by younger historians since Herodotus places Perdiccas I as the first Macedonian king. Of course, apart from the fact that it is known that Herodotus served the political expedients of the time, others of his time disagree, apart from Satyr, who adds Koinos and Tyrimmas to the list, Marsyas of Pella, Theopompos and Justin agree that the Caranos was the father of Perdiccas. Furthermore, Plutarch claimed in his biography of Alexander the Great that all his sources agreed that Caranos was its founder. Based on these, Herodotus' claim could be propaganda against the Argeadian family, contrary to the claim of some scholars who believe that the opposite is happening, i.e. it was propaganda of the Argeadian court, which probably intends to reduce the importance of the name "Perdiccas » to the rival family branches after the accession of Amyntas.
In any case, we should always keep in mind that political expediency is not something that appeared today, but has existed since ancient times. 

Koinos should not be related to his namesake Koinos, the son of the Macedonian nobleman Polidemocratis and a soldier in the ranks of Alexander the Great.

Satyrus (PHerc. 558  OCD, q.v. Satyrus  Athenaeus, vi. 248; xii. 541; xiii. 556  A. S. Hunt, Oxyrhynchi Papyri, vol. 9 (1912), no. 1176, pp. 124–182)
Ηρόδοτος, Ἱστορίαι (8.137.1-8.139.1)
Ευσέβιος της Καισαρείας : Παντοδαπή ιστορία
Kleine philologische Schriften: Zur griechischen Literatur By Friedrich Wilhelm Ritschl Page 454 (1866) Leipzig
The history of Alexander the Great by Charles Alexander Robinson Page 169 (1953)