Owning your own home

Even without the freehold (company) being involved? The idea of buying a leasehold property without the freeholder being aware scares the bejesus out of me!

At common law a lease is a piece of property like any other and can be freely assigned. Most leases will contain some sort of restriction on transfer - technically "a covenant against alienation" - but not all do. If there's no covenant against alienation, or the covenant against alienation doesn't require the landlord's consent or similar, then there's no reason why the freeholder necessarily has to be involved.

Where there is a covenant against alienation, and there are conditions on the right to assign - freeholder's consent, execution of a Deed of Covenant etc. - or even if it prohibits assignment completely, the registered proprietor can still assign the lease and the assignment will be effective. However, if the assignment is made in breach of the terms of the lease then this will normally give the freeholder the right to forfeit the lease, and the law still views a breach of a covenant against assignment as a serious matter. It's one of the few breaches of a lease which are still regarded as irremediable.