Forged by the friendship of Hashirama Senju and Madara Uchiha, Naruto's Konoha village was the first of many to be formed. The village was established by the two as a dream place where families would grow up with love, peace would flourish, and most importantly, children wouldn't have to go to war. To oversee all these things, a Hokage for the village was installed as someone who would be strong enough to protect everyone.
Over the years, Konoha has seen the rise and fall of many Hokage, with some of them going on to make a great name for themselves and getting their names written in history books and others having seen rather unsuccessful reigns and being considered failures for the most part.
The Candidates For The Weakest Hokage
The Hokage are all mighty shinobi so it goes without saying that, to some extent, all of them have been powerful and capable in their own way. However, that's not to say that they were all equally matched. The First Hokage, Hashirama Senju, was incredibly powerful and his strength was so ridiculous that he was hailed as the 'God of Shinobi' across the Five Great Nations. Hashirama's strength was such that he could even match Madara Uchiha in battle and defeat him, which clearly takes him out of the conversation for the weakest Hokage spot. His brother, Tobirama Senju, followed him and, while not as strong, Tobirama was certainly impressive as well. He didn't have the godly powers of his brother but he could fight the Uchiha and, when close to his full power, scare even the likes of Orochimaru by merely lifting a finger.
Hiruzen Sarutobi, the Third Hokage, was considered to be a legendary ninja whose strength surpassed even that of Hashirama Senju in his prime. Even at his old age, he was powerful enough to fight Orochimaru along with two Edo Kage and win the fight at the cost of his life. Like Hashirama, Hiruzen was, quite easily among the strongest Hokage of all time, and eventually, he was succeeded by the legendary Fourth Hokage, Minato Namikaze. Despite being quite young, Minato's strength was such that he was considered to be untouchable in terms of power by the likes of Jiraiya and Hiruzen. Yet, his untimely death meant that he never hit his full potential ever.
Tsunade Senju, the Fifth Hokage, was certainly one of the weaker ones as she went on to become the Hokage way past her prime and her strength was generally not comparable to the other Kage. In the Fourth Great Ninja War, Tsunade wasn't even the strongest Kage with the likes of Ay and Onoki being considered stronger. Tsunade was succeeded by Kakashi Hatake who, just like her, wasn't all that powerful during his time as a Kage. Kakashi had already lost his Sharingan at this point and this weakened him quite a bit. With Naruto Uzumaki, the Seventh Hokage, being considered the strongest of all time, it is quite clear that the weakest of all Hokage is one of Kakashi Hatake and Tsunade Senju.
Who Is The Weakest Hokage: Kakashi Or Tsunade?
As has already been established, the weakest Hokage of Konohagakure is between Kakashi Hatake and Tsunade Senju. In fact, both Kakashi and Tsunade are quite close to each other in terms of strength in Naruto. However, their fighting style differs a lot from each other. While Tsunade is more of a tank and a powerhouse, Kakashi relies more on tactics in battle and is quite calm and calculating while also not lacking any power. Without a doubt, both Kakashi Hatake and Tsunade Senju are skilled Kage.
For Tsunade Senju, however, the reign as the Hokage began when she was quite old and past her prime. This was demonstrated in the story on several occasions when her true appearance made itself known following her usage of the mitotic regeneration jutsu. Tsunade also struggled in quite a lot of battles such as the one against Madara Uchiha, and against Pain, she couldn't engage in combat or prevent him from blowing up the village despite saving a lot of lives. As for Kakashi, often, fans believe that losing his Sharingan made him weaker. However, this couldn't be further from the truth.
On the contrary, Kakashi got even stronger as a Kage after losing his Sharingan and the Naruto light novels suggest as much. Without the eye draining his chakra reserves, Kakashi could fight for longer and make better use of his chakra. What's more, he developed many powerful techniques, such as the Purple Electricity to become a more diverse fighter. In the Boruto anime, Kakashi Hatake, despite being way past his prime Hokage days, was able to match Kashin Koji in combat for a while, which just goes to suggest that he's a monstrous fighter who has only grown stronger with time.
All things considered, Tsunade Senju is certainly the weakest Hokage age in the Naruto series as not only is she the weakest of all the Sannin but is also way beyond her best days during her time as the Hokage. That's not to say that Tsunade wasn't a good Hokage. Time and again, she proved that she is worthy of the title of the Fifth Hokage by demonstrating her inherited Will of Fire and throwing her life on the line to defend all those precious to her. Tsunade was certainly a very successful Hokage, just not as strong as the rest that the fans got to see in the story.