A leasehold problem can turn on any point in the life of the arrangement, so the rules need to be held together as a whole. This chapter begins with what makes a lease rather than a licence — exclusive possession, term certain and the position of joint occupiers — before moving to the formalities for legal and equitable leases, and how registration, priority and implied periodic tenancies determine who is bound. It then works through the enforcement of leasehold covenants under the pre- and post-1996 regimes, the implied repairing obligations, and the rules governing assignment and subletting. Finally it covers the ways a lease ends, including forfeiture, the section 146 notice and relief for tenants and subtenants, and closes with the routes for recovering unpaid rent.