A weird thing to contemplate these days, but at one time, the 1400's specifically, all knowledge was old knowledge. There were no inventions, there were no improvemnets in any human endeavour whatsoever. Things were only done as they had been done or had been done by the Greeks or Romans.
Pastels were invented in the 15th century.
in the early 15th century
The 15th Century.
the 15th century
It is when it was the 15th century, that is, maybe.
people in Hungary in the 15th century
The quadrant was invented during the renaissance, around the 15th century.
During the renaissance 15th- 16th century
Golf was invented in the 15th century by the Scots
Enameling was invented by John Michael Kohler around the 15th century
It was in the 15th century, maybe, I think so?!
late 15th century