Jerusalem Day, the 28th day of the month of Iyar, is also the 100th anniversary of the aliyah (immigration) of Rabbi Avraham Yitzchak HaCohen Kook, the first Chief Rabbi of the Land of Israel and spiritual father of several generations of scholars and students in Israel and abroad.
Rabbi Kook (1865-1935), known for his saintly character, love of Israel, Torah and Jewish-legal expertise, and deep spirituality, is recognized as the progenitor of much of modern religious Zionist thought and philosophy.
Read here about his 1904 arrival in Jaffa to become the regional rabbi.
In addition, the 28th of Iyar is the traditional date of the death of the prophet Samuel. His gravesite, known as Nebi Samuel, lies just north of Jerusalem, and was also liberated during the Six Day War. Arutz-7's Adir Zyk writes in B'Sheva that until 1730, the gravesite was under Jewish ownership, and that each year on this day, thousands of Jews would hold a Lag BaOmer/Meiron-type event there. In 1730, however,
"Jerusalem Mufti Muhammad Al-Halili managed to steal the site's ownership, closed the grave, and forbade Jews from entering the area. The traditional commemorations stopped, and [after a while] the individual Jews who arrived had to pay the Arab guard to let them in. Because of the strategic importance of the site, fierce battles were waged there during World War I and the War of Independence. The Six Day War conquest of Nebi Samuel restored us the ownership of the site."