Simon: They begin at least 100 years after his claimed life.
To drive this point home, the post after yours mentions the following:
Mara Bar Serapion (born 50 AD). The original letter that may contain references to Christianity was written sometime between 73 AD and 300 AD.
Early Christian Writers (ca 50-157 AD), bearing in mind that none of their original writings have been found, just copies of copies of copies, none before the second century, if I am not mistaken.
Thallus (ca 55 AD), whose writings are lost. A reference (800 AD) to a reference (220 AD) of his writings appears to be what remains.
Josephus (ca 93 AD), whose mentions of Jesus are either mistaken or very likely a forgery.
Pliny the Younger, born around 61 AD.
In other words, god took on a body of flesh, came to Earth, performed miracles and gave moving speeches, caused an earthquake and eclipse and raised many dead on the day he died... and no one thought to talk about him for some 50-200 years.