Microsoft partnered Nokia to make Lumia phones from 2011.
In 2014 Microsoft bought out the mobile phone arm of Nokia and rebranded as Microsoft Mobile.
12 months later Microsoft Mobile devices were being shipped with the Windows 10 Mobile OS.
Sales plummeted and within another year Microsoft announced it would no longer develop new phone hardware, and that Windows 10 Mobile would only receive maintenance releases and patches, citing its low market share and Microsoft's abandonment of its mobile business.
In 2016 Microsoft Mobile's feature phone business was sold to HMD Global, a Finnish startup backed by former Nokia executives.
I can't think why anyone would want to buy a Windows phone. They were never popular and, now that they've been discontinued, there's little (if any) support for the apps on them.