The Tiger was fielded, designed, and everything before the Panther AFAIK.
"
The development of one of the most famous tanks of World War II started in 1937 and first massive Tiger I heavy tank emerged in July of 1942. From 1937 to mid 1941, Henschel produced designs and prototypes of various medium and heavy tanks such as DW (Durchbruchwagen)I and II, VK3001, VK3601 and VK6501. At the same, Dr.Porsche developed his VK 3001 Leopard medium tank. None of those tanks entered production but provided both companies with valuable experience in tank design and production, which came to be useful in working on the Tiger heavy tank."
http://www.tarrif.net/ (I know the site is supposedly biased etc, but I am just providing some info)
The prototypes were delivered in Sept. 1942, and production started 2 months later. Daimler-Benz then started production, and in February and March of 1943 Henschel and Maschinenfabrik Niedersachen joined in production. Later in war other production (aircraft) was cut back to free up facilities to manufacture parts for Panthers.
The initial vehicles were tested at Erlangen and Grafenw