Joseph & all brothers have died, but there were still descendants.
New King - wanted to stop having the Israelites multiply. Sent supervisors over the Israelites to oppress them with forced labor. Built garrison cities - Pithom & Raamses
"When you act as midwives for the Hebrew women, look on the birthstool:* if it is a boy, kill him; but if it is a girl, she may live.” (Exodus 1:16)
This shows the harsh and hardship of the King of Egypt. Pharaoh did not want boys to live and shows the emotional toll put onto the midwives at the time with having to kill their boys.
The midwives feared God and did not do what the king of Egypt asked them to do - they let the boys live. This shows to always have faith in God, and they showed they had a sense of conscience.
Because the midwives listened to God and did not kill the boys, God made the people multiply and grow in numbers. Thus showing that God keeps his promises and can grant you things if you follow in his light.