When were the sonnets first published?

Shakespeare's Sonnets were first published in 1609, by the London printer Thomas Thorpe. Sonnets 138 and 144 had appeared earlier, in the 1599 anthology The Passionate Pilgrim.

The fashion for sonnets lasted from about 1580 until the very early 1600's - and for those twenty years sonnets were as cool and hip as rap is today. So by publishing in 1609, Shakespeare's sonnets had missed the boom years.

But there are many references to sonnets written by Shakespeare much earlier than this (and we can see from the subject matter of many of the sonnets that they must have been written long before they were published). So it looks like Shakespeare's sonnets were originally passed round by hand, and only published as an afterthought (after Shakespeare had already become the most famous living playwright).