The line Et in Arcardia ego has been used in many works of art and literature. The first clear use, which established it as a set phrase/motif, is a painting by Guercino from c.1620, showing two shepherds against an idyllic pastoral background, looking at a skull and blowfly on a pedestal; this line is inscribed on the pedestal. The next well-known use is as the title a painting by Poussin from 1637–8, similarly showing pastoral characters and background, but this time contemplating a tomb.

The meaning of the phrase is very ambiguous, without context. Your literal translation And in Arcadia, I is essentially correct, but there a few points to note. Et can mean even as well as and; and Latin often omits forms of the verb to be where English would include it. So it’s usually understood as the slightly more natural (though still ambiguous) phrase Even in Arcadia, I am.

So who is this I in the line? This is understood from the context of the paintings — both of which show symbols of death, in an otherwise idyllic pastoral setting. Arcadia was a byword for such a pastoral idyll; so the I is generally understood to be death. So overall the line is traditionally understood as “Even in Arcadia [an ideal pastoral idyll], I [Death] am still present.”

There are many later uses of the line in arts and literature; they generally take this interpretation of its meaning as understood, though some also take advantage of its vagueness/ambiguity to allude to other possible interpretations as well. One notable example, which explicitly discusses its possible meanings, is Tom Stoppard’s play Arcadia.

The wikipedia article for the Poussin painting includes more details and links good sources for much of this.

The line Et in Arcadia ego has been used in many works of art and literature. The first clear use, which established it as a set phrase/motif, is a painting by Guercino from c.1620, showing two shepherds against an idyllic pastoral background, looking at a skull and blowfly on a pedestal; this line is inscribed on the pedestal. The next well-known use is as the title a painting by Poussin from 1637–8, similarly showing pastoral characters and background, but this time contemplating a tomb.

The meaning of the phrase is very ambiguous, without context. Your literal translation And in Arcadia, I is essentially correct, but there a few points to note. Et can mean even as well as and; and Latin often omits forms of the verb to be where English would include it. So it’s usually understood as the slightly more natural (though still ambiguous) phrase Even in Arcadia, I am.

So who is this I in the line? This is understood from the context of the paintings — both of which show symbols of death, in an otherwise idyllic pastoral setting. Arcadia was a byword for such a pastoral idyll; so the I is generally understood to be death. So overall the line is traditionally understood as “Even in Arcadia [an ideal pastoral idyll], I [Death] am still present.”

There are many later uses of the line in arts and literature; they generally take this interpretation of its meaning as understood, though some also take advantage of its vagueness/ambiguity to allude to other possible interpretations as well. One notable example, which explicitly discusses its possible meanings, is Tom Stoppard’s play Arcadia.

The wikipedia article for the Poussin painting includes more details and links good sources for much of this.