Looking on the internet deeply has found these results:

was known a long time before is the most popular phrase on the web.

was known from a long time before 11 results on the web	was known a long time before 125 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
The behaviour of a narcissistic parent is demontrated in the 1981 (yes, it was known from a long time before) film "Mommy dearest" with Faye Dunaway.	Nov 13, 2015 ... Alexandre. And the truth EVERYTHING was known a long time before! In fact, it was known a long time before Adrian Antoniszoon found it (cf. Struik D.J. A Concise History of Mathematics, 3rd edition, Dover, New York, 1967). That the year had 365.25 days was known a long time before Thales to the Egyptians. }Repeated changes in the course of the sun across the firmament led the�... http://www.youtube.com/watch?v... Don't believe RT? Here you are In fact, it was known a long time before Adrian Antoniszoon found it (cf. Struik D.J. A Concise History of Mathematics, 3rd edition, Dover, New York, 1967).

was known from a long time before

11 results on the web

was known a long time before

125 results on the web

More popular!

The behaviour of a narcissistic parent is demontrated in the 1981 (yes, it was known from a long time before) film "Mommy dearest" with Faye Dunaway.

Nov 13, 2015 ... Alexandre. And the truth
EVERYTHING was known a long time before!
In fact, it was known a long time before Adrian Antoniszoon found it (cf. Struik D.J. A Concise History of Mathematics, 3rd edition, Dover, New York, 1967).
That the year had 365.25 days was known a long time before Thales to the Egyptians. }Repeated changes in the course of the sun across the firmament led the�...
http://www.youtube.com/watch?v... Don't believe RT? Here you are
In fact, it was known a long time before Adrian Antoniszoon found it (cf. Struik D.J. A Concise History of Mathematics, 3rd edition, Dover, New York, 1967).