Lemnian deeds is a term that refers to the cruel slaughter of someone as revenge (in both cases, a whole gender of people, see below). There are two possible origins for this term: the epic of Jason

Jason

Jason was a late ancient Greek mythological hero from the late 10th Century BC, famous as the leader of the Argonauts and their quest for the Golden Fleece. He was the son of Aeson, the rightful king of Iolcus...

 and the Argonauts

Argonauts

The Argonauts ) were a band of heroes in Greek mythology who, in the years before the Trojan War, accompanied Jason to Colchis in his quest to find the Golden Fleece. Their name comes from their ship, the Argo, which was named after its builder, Argus. "Argonauts", therefore, literally means...

, and that of Herodotus narrative of the Pelasgians

Pelasgians

The name Pelasgians was used by some ancient Greek writers to refer to populations that were either the ancestors of the Greeks or who preceded the Greeks in Greece, "a hold-all term for any ancient, primitive and presumably indigenous people in the Greek world." In general, "Pelasgian" has come...

. Interestingly, the gender of the slaughtered victims is the opposite of the one in the other version.

As is usual in other nationalistic epics

Epic poetry

An epic is a lengthy narrative poem, ordinarily concerning a serious subject containing details of heroic deeds and events significant to a culture or nation. Oral poetry may qualify as an epic, and Albert Lord and Milman Parry have argued that classical epics were fundamentally an oral poetic form...

 as well, other people and tribes are deemed to have barbaric tendencies. Besides, Pelasgians of Lemnos

Lemnos

Lemnos is an island of Greece in the northern part of the Aegean Sea. Administratively the island forms a separate municipality within the Lemnos peripheral unit, which is part of the North Aegean Periphery. The principal town of the island and seat of the municipality is Myrina...

 spoke pre-Greek Lemnian

Lemnian language

The Lemnian language is a language of the 6th century BC spoken on the island of Lemnos. It is mainly attested by an inscription found on a funerary stele, termed the Lemnos stele, discovered in 1885 near Kaminia. However, fragments of inscriptions on local pottery show that it was spoken there by...

, and were technologically inferior (as can be seen from the weapons found in burials), which further promoted their primitive nature.

Jasonian origin

It is said that Pelasgian women decided to kill their men, due to the men's cheating with the mainland Thracian women. In anger, the women slaughtered the men in their sleep and lived without men for many years, until Jason and the Argonauts

Jason

Jason was a late ancient Greek mythological hero from the late 10th Century BC, famous as the leader of the Argonauts and their quest for the Golden Fleece. He was the son of Aeson, the rightful king of Iolcus...

 arrived during The Quest for the Golden Fleece.
They mingled with the women and created a new race: the Minyae.

Pelasgian origin

Michael Stewart relates the story of Herodotus

Herodotus

Herodotus was an ancient Greek historian who was born in Halicarnassus, Caria and lived in the 5th century BC . He has been called the "Father of History", and was the first historian known to collect his materials systematically, test their accuracy to a certain extent and arrange them in a...

thus:

The historian, Herodotus, relates the story that when the Pelasgians were driven from Attika (Attica) they kidnapped a number of Athenian women and took them to Lemnos; the women were defiant and taught their children to act and speak like Athenians; the Pelasgians would not accept such rebellious attitudes and killed the captive mothers and children and thus the term Lemnian Deeds became an enduring insult to the honor and manhood of the inhabitants.