I have attached a print version of the charter for the Hudson's Bay Company, which is similar to all original royal charters for the oldest corporations. You will note, at line 67, that the crucial statement is made that the company shall be considered a "person" (I pasted in the entire clause):

WEE DOE make ordeyne constitute establish confirme and declare
62 by these Presentes and that by the same name of Governor &
63 Company of Adventurers of England Tradeing into Hudsons Bay they
64 shall have perpetuall succession And that they and theire
65 successors by the name of Governor and Company of Adventurers of
66 England Tradeing into Hudsons Bay bee and at all tymes hereafter
67 shall bee persons able and capable in Law to have purchase
68 receive possesse enjoy and reteyne Landes Rentes priviledges
69 libertyes Jurisdiccions Franchyses and hereditamentes of what
70 kinde nature and quality soever they bee to them and theire
71 Successors And alsoe to give grant demise alien assigne and
72 dispose Landes Tenementes and hereditamentes and to doe and
73 execute all and singuler other thinges by the same name that to
74 them shall or may apperteyne to doe And that they and theire
75 Successors by the name of the Governor and Company of Adventurers
76 of England Tradeing into Hudsons Bay may pleade and bee impleaded
77 answeare and bee answeared defend and bee defended in whatsoever
78 Courtes and places before whatsoever Judges and Justices and
79 other persons and Officers in all and singular Accions Pleas
80 Suitts Quarrells causes and demandes whatsoever of whatsoever
81 kinde nature or sort in such manner and forme as any other our
82 Liege people of this our Realme of England being persons able and
83 capable in Lawe may or can have purchase receive possesse enjoy
84 reteyne give grant demise alien assigne dispose pleade defend and
85 bee defended doe permit and execute And that the said Governor
86 and Company of Adventurers of England Tradeing into Hudsons Bay
87 and their successors may have a Common Seale to serve for all the
88 causes and busnesses of them and theire Successors and that itt
89 shall and may bee lawfull to the said Governor and Company and
90 theire Successors the same Seall from tyme to tyme at theire will
91 and pleasure to breake change and to make a new or alter as them
92 shall seeme expedient.

Every corporate charter is premised on this fundamental point. The Dutch East India Company has a similar provision but the English common law tradition uses the word "person" as a legal term in a way that the civil law tradition of the Continent did not, at least uniformly, prior to the Code Napoleon.