Bounty:

Whitebeard is currently the strongest pirate in the world. He is said to be the pirate closest to obtaining the legendary treasure, One Piece. It is said that Whitebeard used to have numerous battles with the late Pirate King, Gol D. Roger, and was marked as his equal in the past.

Whitebeard appears to have some health problems, possibly stemming from his advanced age or from his ferocious encounters with other great pirates during his earlier days. He is always surrounded by nurses and is hooked up to intravenous tubes. But despite this, he still drinks rum by (and directly from) the barrel. Even with his health issues, he is still considered the world’s strongest pirate, which raises the question of how powerful he must have been in his prime.

When he first appears, he receives a letter from Red-Haired Shanks on behalf of Shanks’ newest crewmate Rockstar. However, before even reading the letter, Whitebeard throws it away, claiming that if Shanks wants to talk, then he should visit in person. He even asks Rockstar to tell Shanks to prepare an expensive bottle of sake when Shanks comes to visit. When Shanks finally breaks through a blockade for their meeting, he calls him “boy”, showing his feelings for the much younger captain, compared to his own age and prestige in the “New World” section of the Grand Line.

(Source: Wikipedia)