Professor Xavier has a Secret:

He brainwashed Wolverine
to make him loyal

Details of the Secret:
Professor X brainwashes WolverineWhen Wolverine first joined the X-Men, Xavier operated on Wolverine’s brain telepathically. Although removing the mental blocks and controls installed by Romulus was done with Wolverine’s consent, Xavier went on to remove some of Wolverine’s memories – notably those involving Romulus – and to instill in him a loyalty to the X-Men (and by implication, to Xavier himself) that he did not feel before then.

Kept from: Giant-Size X-Men #1, May 1975.

Who knew the secret: Xavier and Moira McTaggert. It’s likely that Romulus worked it out, too.

Secret revealed: Wolverine: Origins #29, December 2008.

Notes:Professor X continues to brainwash Wolverine Unusually, when this secret was revealed to readers, it was unknown to Xavier and known to Wolverine – Xavier having recently lost many of his memories and Wolverine having regained all of his. Technically, it was revealed to Wolverine in House of M #8, January 2006, in which he regained all of his memories, but he did not share this information for while.

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