The Jewish Passover comes in April and is widely observed by all of the faith. It can seem a little confusing to the outside as to why it is observed with such enthusiasm by the Jewish people and the answer is simple, it commemorates the suffering and experiences of Jews through the many centuries the religion has existed, despite great pressure and persecution. When one considers the story of the Passover it comes as little wonder why such things as Seder Plates, like those from https://cazenovejudaica.com for example are sought after.
If you look at the story you have to question Pharaohs mindset. The Jews had been welcomed to Egypt as they fled their own land escaping a plague. The Egyptians were initially pleased as they brought knowledge and extra hands for building. However, as the Jews settled and thrived the Egyptians resented them and enslaved them. The Jews wanted to leave and return to Israel. The Pharaoh theorised that they could become a threat to his lands so kept them in the country.
Moses, after a visitation from Yahweh, went to Pharaoh and told him to release them or plagues would be visited on the land. After the first one, water being turned to blood occurred you would think that Pharaoh would have said yes. It took a further nine. Frogs, lice, flies, livestock pestilence, boils, hail, locusts, darkness, and the killing of firstborn children.