Leonid Boicu, one of the greatest Romanian contemporary historians, was born in Dondoseni, Soroca district (Republic of Moldavia), on May 1-st, 1931, and died in Iasi (Roumania), on May 2-nd, 1997. His life was strongly marked by the quite unfavourable political circumstances, following the Second World War, when he and his family, too, prefered to move (after the Soviet ultimatum was sent to Romanian Government, in 1940) for ever in Roumania. So, he arrived in the former Moldavia’s capital, Iaşi, where he studied at the “Al. I. Cuza” University, founded his proper family, and worked from the early beginning up to the end of his life at the “A.D. Xenopol” Institute of History, belonging by the Romanian Academy. As a brilliant specialist, not only in the various fields of Romanian modern history, but especially on the diplomatic history of modern times, including the international relationships of the Romanian Principalities during the Eighteenth and Nineteenth Centuries, Leonid Boicu shared his very large and generous professional experience and deep knowledges with his younger colleagues, both from “A.D. Xenopol” Institute and “Al. I. Cuza” University, without waiting any reward. Unfortunately, he did not enjoyed such (moral and material) reward in the same measure which his works, thought, conduct and entire activity deserved. Among the most important works signed by the great historian Leonid Boicu, it can be mentioned: his doctoral paper Austria şi Principatele Române în vremea războiului Crimeii. 1853-1856 (Bucharest, 1972); Adevărul despre un destin politic. Domnitorul Gr. Al. Ghica. 1849-1856 (Iaşi, 1973); Geneza “chestiunii române” ca problemă internaţională (Iaşi, 1975); Diplomaţia europeană şi triumful cauzei române. 1856-1859 (Iaşi, 1978); Principatele Române în raporturile politice internaţionale. Secolul XVIII (Iaşi, 1986); Din istoria diplomaţiei europene: anul 1859 la români (Iaşi, 1996); Principatele Române în raporturile politice internaţionale. 1792-1821 (Iaşi, 2001) and many other. In the present paper, there are some opinion, thoughts and recollections, written by one of his former colleague, neighbour and disciple, as a sign of deepful and posthumos respect given to an exceptional mentor and authentic role model.