<human>: DiBiase was born in Miami, Florida. He is the biological son of wrestler Helen Nevins and Ted Wills, an entertainer and singer. He is the adopted son of wrestler "Iron" Mike DiBiase, who was Italian-American. DiBiase is of mostly German and English ancestry.

DiBiase entered All Japan Pro Wrestling (AJPW) in 1983. He won the NWA United National Championship on October 14, 1983 in a tournament defeating Jerry Lawler by forfeit. Two months later on January 28, 1984, DiBiase lost the title to Michael Hayes. DiBiase's mother Helen Hild died two months later in March 4, 1984.  In August 1985, DiBiase formed a tag team with fellow gaijin: Stan Hansen and the two became the PWF Tag Team Champions when Hansen chose DiBiase to replace Bruiser Brody who left for New Japan Pro Wrestling (NJPW). Later that year, DiBiase and Hansen entered the 1985 World's Strongest Tag Determination League and would emerge victorious finishing in first place with 7 points.  On July 3, 1987, DiBiase and Hansen would lose the PWF Tag Team Championship to Jumbo Tsuruta and Tiger Mask, ending their two-year reign as champions. Eight days later on July 11, DiBiase and Hansen regain the titles for a second time, but would be stripped of the titles shortly after due to DiBiase leaving AJPW for the WWF.  In September 1993, DiBiase returned to AJPW and reformed his team with Hansen. The two immediately saw success as they defeated The Holy Demon Army on September 3, 1993 for the World Tag Team Championship. Two months later on November 13, 1993, DiBiase and Hansen would be stripped of the titles so they could be put on the line for the 1993 World's Strongest Tag Determination League. DiBiase would enter the tournament, but would only wrestle one match on November 14 where he and Hansen defeated Tracey Smothers and Richard Slinger before he suffered neck and back injuries which forced him out of the tournament (Giant Baba ended up replacing him). CANNOTANSWER

Answer the following question by taking a quote from the article: when did he join wwf?
<bot>: Hansen would be stripped of the titles so they could be put on the line for the 1993 World's Strongest Tag Determination League.