Rav Yisrael of Shklov's Attempt to Reinstitute Semicha
This week's Ladaat newsletters includes a very interesting summary of the Gr"a's student Rav Yisrael of Shklov's attempt to reinstitute Semicha. The reason for him doing so was in order to hasten the Geula.
The Radvaz on the Rambam in Hil. Sanhedrin 4:11 writes that those who temporarily reinstituted Semicha in the time of Mahari Beirav and Rav Yosef Karo were mistaken in their understanding of the Rambam for a few reasons. One of the reasons he gives was:
Translation:ותו דבני ראובן עתידים לבוא ולעשות מלחמות לפני בוא מלך המשיח ומאן לימא לן שלא יהיה בהן סמוך מפי סמוך והוא יסמוך אחרים
...And furthermore, the children of Reuven are destined to come and make wars before the King Mashiah comes, and who is to say to us that there will not be among them one who had Semicha from another who had Semicha, and he can give Semicha to others...Only hinted to in the newsletter, but explained elsewhere, he was further supported by 2 additional sources. The first was the testimony of Eldad Hadani that when they learn, they say, "So said Yehoshua bin Nun Mipi Moshe Mipi Hagevura." The second source was a letter sent by the Benei Moshe to "the tribes of Yehuda and Binyamin in Yerushalayim" in the year 5406 that they judge "with Arba Mitot Beit Din based on the great elder in the Beit Hakeneset".
Based on this Radvaz and the other 2 sources, Rav Yisrael of Shklov sent a scholar - Rav Baruch of Pinsk - to search for the 10 tribes, of whom reports were coming of their existence and whereabouts. He asked Rav Baruch to ask them if they can send one of their elders - who presumably was given Semicha from another who was given Semicha where the Semicha went back to Moshe Rabbeinu - to Israel to then give Semicha to everyone else.
Ultimately and unfortunately, his attempt failed. You can read about what happened to Rav Baruch of Pinsk in the last section here.
(As an aside, in one of his letters to the 10 tribes, he mentions a Yalkut Shimoni Tehilim Remez 779 that when HKB"H wants to gather in Israel, He will gather half the tribe of Menashe first, as it says לי גלעד לי מנשה.)