 Complete the following phrase:  The double-headed eagle was a main element of the coat of arms of the Russian Empire 17211917, modified in various ways from the reign of Ivan III 14621505 onwards, with the shape of the eagle getting its definite Russian form during the reign of Peter the Great 16821725. It continued in Russian use until abolished being identified with Tsarist rule with the Russian Revolution in 1917; it was restored in 1993 after that years 