Final answer:
Joseph's family came to buy food from Egypt around 1800 BCE during the second year of the biblical famine, according to the historical timeline based on biblical chronology.
Step-by-step explanation:
The biblical account of Joseph's family coming to buy food from Egypt is found in the book of Genesis. According to the historical timeline around 1800 BCE based on the biblical chronology, Joseph's family came to Egypt during the second year of famine, as mentioned in Genesis 45:6. This was to seek relief from the widespread famine that had not only affected Egypt but also the surrounding lands, including Canaan where Joseph's family resided.
The story unfolds in the context of Joseph rising to power in Egypt after interpreting Pharaoh's dreams and predicting seven years of plenty followed by seven years of famine. The famine was severe, and when Jacob, Joseph's father, learned that there was grain in Egypt, he sent his sons to buy provisions. As the story goes, Joseph's management of the Egyptian grain resources during the plentiful years and the subsequent rationing during the famine saved Egypt and the surrounding nations from severe starvation.
The impact of famines on populations, historically, can be quite severe, as seen in the various famines mentioned such as the Ukrainian Holodomor, the famine during the Little Ice Age in Europe, and the Ethiopian famine. These events highlight the complex interplay of political decisions, economic policies, and environmental factors in causing and exacerbating famines.