When Jacob wrestled with the angel (some say he wrestled with God, while others say it was an angel) he overcame his opponent, and was blessed. "Thy name shall be called no more Jacob, but Israel"
And much earlier this was prophesied
23 The LORD said to her,
"Two nations are in your womb,
and two peoples from within you will be separated;
one people will be stronger than the other,
and the older will serve the younger."
Jacob and Esau would become the fathers (so to speak) of two nations. Jacob the nation of Israel. Israel would eventually have 12 tribes.
And now, Revelation 12 speaks of a woman clothed with sun and moon with a diadem of 12 stars.
1A great and wondrous sign appeared in heaven: a woman clothed with the sun, with the moon under her feet and a crown of twelve stars on her head. 2She was pregnant and cried out in pain as she was about to give birth.
A similar instance occurs in the book of Genesis, this time with Joseph. Genesis 37:9
9 Then he had another dream, and he told it to his brothers. "Listen," he said, "I had another dream, and this time the sun and moon and eleven stars were bowing down to me."
Why 11? Because Jacob would become the 'father' of the 12th tribe of Israel. The woman in Revelation 12 is the nation of Israel, to which Jesus Christ was born. Satan intended to destroy Christ, but failed. He now sets to destroy Israel and her other offspring.
This offspring being the churches/people who keep the commandments of God.
So to answer your question. The great Tribulation is called the time of Jacob's (Israel's) trouble, because this is when Satan's persecution will be the strongest.
ETA: The 12 stars around the woman are the 12 tribes of Israel.