Aeningia is an island mentioned in the Natural History by Pliny the Elder

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

, written in the 1s century CE. According to Pliny, Aeningia was inhabited by Sarmatians

Sarmatians

The Iron Age Sarmatians were an Iranian people in Classical Antiquity, flourishing from about the 5th century BC to the 4th century AD....

 (Sarmati), Veneti (Venedi), Scirii

Scirii

The Scirii were an East Germanic tribe of Eastern Europe, attested in historical works between the 2nd century BC and 5th century AD.The etymology of their name is unclear...

 (Sciri) and Hirri, bordering Vistula

Vistula

The Vistula is the longest and the most important river in Poland, at 1,047 km in length. The watershed area of the Vistula is , of which lies within Poland ....

. Aeningia was probably a corrupted form of Aestingia (Estland) and referred to the area of the present-day Baltic states

Baltic states

The term Baltic states refers to the Baltic territories which gained independence from the Russian Empire in the wake of World War I: primarily the contiguous trio of Estonia, Latvia, Lithuania ; Finland also fell within the scope of the term after initially gaining independence in the 1920s.The...

 and northern Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

.

Some early European historians interpreted the name as a corrupt form of Finland

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

, constructing a hypothetical Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 name Finningia

Finningia

Finningia is an old Latin name for Finland, along with Fennia, Finnia and most often used Finlandia. The name first appears in the work of Olaus Magnus from 1539, who placed Finningia olim regnum on the Scandinavian map to indicate the unhistorical past kingdom of Finland...

as the original name. This probably originated from Olaus Magnus

Olaus Magnus

Olaus Magnus was a Swedish ecclesiastic and writer, who did pioneering work for the interest of Nordic people. He was reported as born in October 1490 in Östergötland, and died on August 1, 1557. Magnus, Latin for the Swedish Stor “great”, is a Latin family name taken personally, and not a...

 who was the first to place Finningia olim regnum on the map in 1539 or from Jacob Ziegler

Jacob Ziegler

The humanist and theologian Jacob Ziegler of Landau, was an itinerant scholar of geography and cartographer, who lived a wandering life in Europe...

, who placed Finlandia and Einingia next to each other in present-day southwestern Finland in 1532.