Wikipedia
Actaeus ( Greek: ) was the first king of Attica, according to Pausanias. He was the father of Agraulus, and father-in-law to Cecrops, the first king of the city of Athens. Actaeus is said to have ruled over a city named Acte (, Akte). The location of this city is uncertain, but given that Acte means "coast" or "promontory", one can speculate that this is a culture reference to local or native population groups inhabiting some coastal areas of the Attic promontory, perhaps sharing language, or ethnic ties. This concords with evidence from the archaeological record which attest widespread coastal settlement in the Neolithic period (OED ad. loc. cit. Attica). One tradition states that Actaeus gave Attica its name before it was changed to Cecropia by Cecrops, others claim that Atthis, a daughter of Cranaos, the second king of Athens, is Attica's namesake. Actaeus had a daughter – Agraulus, who was married to Cecrops, the first king of the city of Athens.
According to the Bibliotheca, on the other hand, Cecrops was the first king of Attica, and the three daughters were his own.
Another Actaeus is mentioned in Greek mythology as the father of Telamon, and grandfather of Ajax of Salamis.
Actaeus is a Cambrian organism with a resemblance to the great appendage arthropods. It is known from a single specimen recovered from the Burgess Shale of British Columbia, Canada. The specimen is over 6 cm long and has a body consisting of a head shield, 11 body tergites, and a terminal plate.