Jews
Prior to 1948, approximately 800,000 Jews were living in lands which now make up the Arab world (excluding Israel). Of these, just under two-thirds lived in the French-controlled Maghreb region, 15–20% in the Kingdom of Iraq, approximately 10% in the Kingdom of Egypt and approximately 7% in the Kingdom of Yemen. A further 200,000 lived in Pahlavi Iran and the Republic of Turkey. Today, around 26,000 Jews live in Arab countries and around 30,000 in Iran and Turkey. A small-scale exodus had begun in many countries in the early decades of the 20th century, although the only substantial aliyah came from Yemen and Syria. The exodus from Arab and Muslim countries took place primarily from 1948. The first large-scale exoduses took place in the late 1940s and early 1950s, primarily in Iraq, Yemen and Libya, with up to 90% of these communities leaving within a few years. The peak of the exodus from Egypt occurred in 1956. The exodus in the Maghreb countries peaked in the 1960s. Lebanon was the only Arab country to see a temporary increase in its Jewish population during this period, due to an influx of refugees from other Arab countries, although by the mid-1970s the Jewish community of Lebanon had also dwindled. In the aftermath of the exodus wave from Arab states, an additional migration of Iranian Jews peaked in the 1980s when around 80% of Iranian Jews left the country.[citation needed]

Q: Prior to 1948, how many Jews were living in lands which now make up the Arab world (excluding Israel)?
800,000