Why does it say "Al Yirmeyah"?
Radak: This is like El Yirmeyah.
What is special about the fourth year of Yehoyakim?
Rashi (from Seder Olam Rabah 24): That is when the decree was sealed that they will be exiled and drink the cup of anger (verse 16). Before this, Hashem told the Navi to rebuke them - perhaps they will repent, and the decree will not be sealed.
Here it says that Nebuchadnetzar became king in the fourth year of Yehoyakim. In Daniel (1:1), it says that in the third year of Malchus Yehoyakim, Nebuchadnetzar came and besieged Yerushalayim!
Radak (here and Melachim II, 24:1): After three years of Yehoyakim's rule, at the beginning of the fourth year, Yirmeyah prophesized that Nebuchadnetzar will come. He came that year, besieged the city and conquered it, and took Yehoyakim to Bavel. He returned him to Yerushalayim, and for three years he was faithful to Melech Bavel. After this, he rebelled. This was at least seven years into his kingship, or more; we do not know how long he was in Bavel before he returned to Yerushalayim. If it was the same year, we must say that he rebelled for four years before troops came from Bavel, for in all he ruled 11 years. If he returned to Yerushalayim after four years in Bavel, his eighth year of kingship, he was faithful for three years after that; he rebelled in his 11th year, and troops came that same year from Bavel.
Radak (Melachim II, 24:1, citing Seder Olam 24 and Megilah 11b): In Nebuchadnetzar's first year of rule, he conquered Ninveh. In his second, he conquered Yehoyakim; it was Yehoyakim's fifth year, and he was a slave to him, and stood [faithful to him] for three years, for there were eight years before he rebelled - four before Nebuchadnetzar's reign, the year he was conquered, and three of servitude. He rebelled, and after three years Nebuchadnetzar came and conquered him a second time. Daniel (1:1) says "in the third year [of Malchus Yehoyakim]" - it was the 11th year of Yehoyakim 1 and the eighth of Nebuchadnetzar. That eighth year Nebuchadnetzar made Yehoyachin king, and he ruled for three months and he was exiled with ha'Charash veha'Masger. We say (Megilah 11b) 'they were exiled in the seventh, 'they were exiled in the eighth' - it was the seventh year from when Yehoyakim was conquered, which was the eighth year of Nebuchadnetzar's reign, for he conquered Yehoyakim in his second year.
Malbim (Melachim II, 24:1, citing Mahari): In Nebuchadnetzar's first year, he came against Yehoyakim. "In the third year" (Daniel 1:1) is simply his third year, i.e. at the end. In his fourth year, the first of Nebuchadnetzar, Nebuchadnetzar took him and some Kelim of Beis Hashem to Bavel. He served him there for three years, returned to Yerushalayim and afterwards rebelled. Nebuchadnetzar came against him a second time, killed him and dragged him around the gates. 2
Malbim (Melachim II, 24:1): It is called the third year, for it is the third year that he ruled by himself (i.e. after he rebelled - PF). We say similarly about Hoshe'a ben Elah and Uziyah. If so, "Kevuras Chamor Yikaver Sachov v'Hashlech me'Hal'ah l'Sha'arei Yerushalayim" (Yirmeyah 22:19) means that they sent his corpse from Bavel to Eretz Yisrael, to drag it in disgrace around the gate of Yerushalayim. Alternatively, when Nebuchadnetzar came against Yehoyachin, he brought Yehoyakim with him, and there he was killed and dragged to disgrace his son who ruled in place of him.
Malbim: However, in Yirmeyah (36) it says that in Yehoyakim's fifth year they called a fast, and Yehoyakim burned Megilas Eichah that Yirmeyah wrote. This teaches that in his fifth year, he was in Yerushalayim! Do not say that this was after he returned to Yerushalayim, and he was a slave to Nebuchadnetzar. When he burned the Megilah, he said "why did you write that Melech Bavel will come
